Origins of Criminal Behavior: Biological Factors

Summary

This educational screencast delves into the complex interplay between biological factors and criminal behavior. It explores the age-old nature versus nurture debate, emphasizing the role of genetics, brain structure, neurotransmitters, and hormones. The lecture highlights the use of twin studies to discern genetic influences, noting the higher concordance rates in identical twins for conditions like ADHD. It also touches on epigenetics, showing how environmental factors can alter gene expression. The discussion suggests that while genetics may predispose individuals, environmental triggers are crucial for the manifestation of criminal tendencies, advocating for a 'nature via nurture' perspective.

Takeaways

• 🧬 The debate between nature and nurture's role in criminal behavior is discussed, suggesting that both genetic and environmental factors are significant.
• 🔬 Studying twins, particularly identical versus fraternal, provides insights into the genetic predispositions to certain behaviors, including criminal tendencies.
• 🧬 Identical twins share the same DNA, which allows researchers to isolate the impact of genetics on behavior compared to fraternal twins who share a womb but not identical DNA.
• 🧬 Epigenetics plays a role in how genes are expressed, showing that even identical twins can have different outcomes due to environmental influences.
• 🧠 The study of psychophysiology reveals that criminals may have different physiological responses, such as fear, which could be linked to their behavior.
• 🧠 The frontal lobe's role in executive functioning and its potential damage leading to impulsive behavior is highlighted, suggesting a neurological basis for criminal behavior.
• 👶 Prenatal factors such as exposure to toxins and birth complications can influence future behavior, possibly predisposing individuals to criminality.
• 🧪 The case of Phineas Gage illustrates how brain injury can drastically change personality and behavior, hinting at the importance of neurological health.
• 🌐 Hans Eysenck's theory of personality is mentioned, suggesting that extroverted and emotionally unstable individuals might be more prone to criminal behavior.
• 📚 The importance of reading the textbook for detailed studies and further understanding of the topics covered in the screencast is emphasized.

Q & A

What is the main topic discussed in the script?

The main topic discussed in the script is the exploration of biological factors that may predispose individuals to criminal behavior, including genetics, brain structures, neurotransmitters, and hormones.

What is the nature versus nurture debate mentioned in the script?

The nature versus nurture debate refers to the longstanding discussion about whether human behavior is determined by genetic inheritance (nature) or by experiences and the environment (nurture). The script suggests that this debate may not be as clear-cut as previously thought.

How can the impact of genetics versus environment on criminal behavior be studied?

The impact of genetics versus environment on criminal behavior can be studied by examining DNA, comparing identical (monozygotic) twins with fraternal (dizygotic) twins, and considering epigenetic factors that influence gene expression.

What is the significance of studying identical and fraternal twins in the context of criminal behavior?

Identical twins share the same DNA, while fraternal twins do not. By comparing their behaviors, researchers can estimate the influence of genetics on criminal behavior, as any differences in behavior would be more likely due to environmental factors.

What are epigenetic factors and how do they relate to the expression of genes?

Epigenetic factors are influences from the environment that can turn genes on or off without changing the underlying DNA sequence. They play a role in how genes are expressed, meaning that even identical twins can have different traits and behaviors due to environmental influences.

What is the concordance rate in the context of twin studies?

The concordance rate refers to the percentage of identical (monozygotic) versus fraternal (dizygotic) twins who both exhibit a particular trait or behavior, such as criminal behavior. It helps to indicate the genetic influence on that trait or behavior.

How does the script suggest that the nature versus nurture debate has evolved?

The script suggests that the nature versus nurture debate has evolved to recognize that both genetic predispositions and environmental factors play significant roles in shaping behavior, rather than one being solely responsible.

What is the role of psychophysiology in understanding criminal behavior as discussed in the script?

Psychophysiology examines the relationship between psychological processes and physiological functions. The script mentions that individuals with criminal tendencies may have different physiological responses to stimuli, such as fear, which could be linked to their behavior.

What is the significance of the Phineas Gage case in understanding the impact of brain injuries on behavior?

The Phineas Gage case is significant because it demonstrates how damage to specific parts of the brain, particularly the frontal lobes, can lead to drastic changes in personality and behavior, suggesting a neurological basis for certain behaviors.

How does the script relate Hans Eysenck's theory of personality to criminal behavior?

The script relates Hans Eysenck's theory of personality, particularly the dimensions of extraversion and emotional stability, to criminal behavior by suggesting that individuals who are extroverted and emotionally unstable may be more prone to criminal activities.

Outlines

00:00

🧬 Biological Factors in Criminal Behavior

This paragraph introduces the concept of biological factors potentially predisposing individuals to criminal behavior. It raises questions about the nature of these factors, such as genetic influences, brain structures, neurotransmitters, and hormones. The paragraph also touches on the age-old debate of nature versus nurture, referencing John Locke's tabula rasa and its adoption by Watson, suggesting that environment can significantly shape a person's behavior. The speaker emphasizes the importance of studying genetics and environment together to understand criminal behavior and mentions the use of DNA and twin studies as methods to explore this impact. The paragraph concludes by hinting at the complexity of the nature-nurture debate and the potential obsolescence of this dichotomy.

05:01

👶 The Study of Twins: Nature vs. Nurture

The paragraph delves into the use of twin studies to understand the influence of genetics versus environment on behavior. It explains the difference between monozygotic (identical) and dizygotic (fraternal) twins, noting that identical twins share the same DNA, which makes them ideal for studying genetic influences. The speaker discusses how concordance rates between twins can indicate the impact of genetics, using examples such as schizophrenia and ADHD to illustrate the point. The paragraph also mentions the case of identical twins, Steven and Robert Spolki, who both exhibited criminal behavior, suggesting a genetic component. The idea of a large prison study to compare monozygotic and dizygotic twins' criminal backgrounds is proposed to further explore the genetic influence on criminal behavior.

10:04

🧬 Beyond DNA: Epigenetics and Environmental Influences

This paragraph explores the complexity of genetic influence on behavior by introducing epigenetics. It explains that while identical twins share the same DNA, environmental factors can affect gene expression, making them not entirely identical. The concept of epigenetics, where the environment signals genes to turn on or off, is discussed, using examples such as the thickening of feet from being barefoot and the development of calluses on guitar players' fingers. The paragraph also mentions that even with identical genes, environmental differences can lead to different expressions of those genes, thus impacting behavior. It concludes with a quote from Adrien Rain, suggesting that genetics contribute moderately to criminal behavior, but environmental factors are also crucial, marking the end of the nature versus nurture debate and emphasizing the interplay between the two.

15:05

🚨 Psychophysiological Correlates of Criminal Behavior

The paragraph discusses the psychophysiological aspects of criminal behavior, focusing on how the nervous system of criminals might respond differently to stimuli compared to non-criminals. It mentions that violent or antisocial individuals often show lower physiological arousal when exposed to graphic images. The speaker uses the example of Travis Pastrana, a daredevil, to illustrate fearlessness and links it to possible biological or genetic differences. The paragraph also introduces the concept of temperament, suggesting it is a stable trait throughout life and can be influenced by prenatal factors such as birth complications and exposure to toxins. The famous case of Phineas Gage is highlighted to demonstrate how brain injury can lead to significant changes in personality and behavior, hinting at the role of neurological factors in criminal behavior.

20:08

🧠 Frontal Lobe Function and Criminal Tendencies

This paragraph continues the discussion on the neurological factors influencing criminal behavior, focusing on the frontal lobes and their role in executive functioning. It describes how damage to the frontal lobes, as in the case of Phineas Gage, can lead to impulsive behavior and personality changes. The speaker mentions that individuals with frontal lobe injuries often exhibit traits similar to those seen in criminals, such as impulsivity. The paragraph also touches on the theories of Hans Eysenck, discussing the relationship between introversion/extroversion and central nervous system arousal. It suggests that extroverted individuals, due to their low arousal levels, might be more prone to seek excitement and engage in criminal behavior. The speaker shares an anecdote about an experiment conducted in a class to demonstrate the differences in saliva production in introverted and extroverted students in response to a sour candy,寓意着 central nervous system arousal.

25:10

🌟 Extroversion, Emotional Stability, and Criminal Behavior

The final paragraph builds on Eysenck's theories, examining the personality traits associated with introversion and extroversion and their potential links to criminal behavior. It discusses how extroverted individuals with low levels of central nervous system arousal might engage in criminal activities to increase their arousal. The paragraph also explores the concept of emotional stability, suggesting that emotionally unstable extroverts might exhibit personality traits similar to those of criminals, such as aggressiveness and impulsivity. The speaker encourages students to read the textbook for more detailed information on the studies mentioned and concludes by mentioning the next topic, psychopathy, which is a favorite subject for further exploration.

Keywords

💡Biological factors

Biological factors refer to the genetic, hormonal, and neurological components that may predispose individuals to certain behaviors. In the context of the video, these factors are discussed as potential contributors to criminal behavior, challenging the simplistic nature versus nurture debate. The script mentions genes, brain structures, neurotransmitters, and hormones as examples, suggesting that there might be inherent traits that influence behavior.

💡Nature versus nurture

This classic debate contrasts the influence of genetic inheritance (nature) and environmental factors (nurture) on behavior and development. The video script uses this debate to frame the discussion on the origins of criminal behavior, suggesting that both genetic and environmental elements play a role. The script references John Locke's 'tabula rasa' concept and Watson's behavioral psychology to illustrate different perspectives within the debate.

💡Genetics

Genetics is the study of genes, heredity, and how genetic variations can lead to different physical and behavioral traits. In the video, genetics are considered as one of the potential biological factors that might influence criminal behavior. The script mentions the ability to study DNA and genes to understand their role in behavior, moving beyond just environmental influences.

💡Twins studies

Twins studies, particularly comparing identical (monozygotic) and fraternal (dizygotic) twins, are highlighted in the script as a method to study the impact of genetics versus environment on behavior. Identical twins share the same DNA, while fraternal twins do not, making them a useful comparison for assessing genetic influences. The video suggests that by examining the concordance rates of criminal behavior among these twin types, researchers can gain insights into the genetic components of such behavior.

💡Epigenetics

Epigenetics is the study of changes in gene expression that do not involve alterations to the underlying DNA sequence. The script introduces epigenetics to explain how environmental factors can influence gene expression, thus affecting traits and behaviors. This concept challenges the idea that identical twins, despite having the same DNA, might develop different characteristics due to environmental influences.

💡Concordance rates

Concordance rates refer to the percentage of identical twins who both exhibit a particular trait or behavior, compared to fraternal twins. In the video, concordance rates are used as a statistical measure to understand the genetic influence on criminal behavior. Higher concordance rates in identical twins would suggest a stronger genetic component.

💡Psychophysiology

Psychophysiology is the study of the physiological basis of psychological processes and behavior. The script mentions psychophysiology in relation to criminal behavior, suggesting that physiological responses to stimuli, such as fear, might differ between criminals and non-criminals. This could imply a biological basis for certain behavioral tendencies.

💡Temperament

Temperament refers to an individual's natural disposition or inborn behavioral tendencies. The video script discusses how temperament, which is relatively stable throughout life, might influence criminal behavior. It gives examples of how temperament can range from being easygoing to being more irritable and how these traits might predispose individuals to certain actions.

💡Prenatal factors

Prenatal factors encompass the conditions and exposures during pregnancy that can influence the development of the fetus. The script mentions prenatal factors such as birth complications and exposure to toxins like nicotine, alcohol, and drugs, which may have long-term effects on behavior, potentially leading to conditions like ADHD or contributing to criminal behavior.

💡Neurological factors

Neurological factors relate to the structure and function of the nervous system, including the brain, and how they affect behavior. The video script touches on the role of the frontal lobes and the amygdala in behavior, suggesting that damage or dysfunction in these areas might lead to changes in personality and an increased likelihood of criminal behavior.

Highlights

Introduction to the exploration of biological factors that may predispose individuals to criminal behavior.

Emphasis on the importance of the textbook for detailed studies and specific research findings.

Discussion of the age-old nature versus nurture debate in relation to criminal behavior.

Historical reference to John Locke's tabula rasa concept and its influence on behaviorist theories.

Proposal to study the impact of genetics versus environment on criminal behavior through DNA analysis.

Explanation of the use of twin studies, particularly identical versus fraternal twins, to understand genetic influences.

Statistics on the heritability of disorders like ADHD and the implications for understanding criminal behavior.

Description of the differences between monozygotic (identical) and dizygotic (fraternal) twins in genetic and environmental terms.

Case study of identical twins with criminal tendencies, highlighting the potential genetic factors in crime.

Introduction to the concept of epigenetics and how environmental factors can influence gene expression.

Example of epigenetics in action: how lifestyle choices can affect gene expression, such as foot thickness in homeless individuals.

Review of research suggesting that genetics contribute moderately to criminal behavior, especially nonviolent crime.

The declaration that the nature versus nurture debate is outdated, emphasizing the interplay between genetics and environment.

Discussion on psychophysiological factors related to criminal behavior, such as fearlessness and physiological responses to fear.

Mention of the famous case of Phineas Gage and the impact of brain injury on personality and behavior.

Eysenck's theory on personality types and how they relate to criminal behavior, particularly introversion and neuroticism.

Encouragement for students to read the textbook for more detailed information and to engage with the material.

Transcripts

could it be that there are biological

factors that predispose someone to

criminal

Behavior what might those biological

factors be this screencast is a brief

introduction we'll cover this in far

more detail during the rest of the

semester and don't neglect your textbook

because the textbook goes into detail

and covers the specific studies which I

won't do here um so don't neglect that

but what is it is is there something

that drives criminal behavior is it

something in the genes is it brain

structures neurotransmitters hormones

what could it be well this really brings

us to the old nature versus nurture

debate I like that picture there and

this debate has gone on for a long long

time uh you might remember John Lock's

conceptualization of the tabar rasa that

was later basically taken up

by uh

Watson so he thought that he could take

any child and based on environmental

interactions or

nurture he could get them to become a

doctor a lawyer or a criminal based on

how you reinforce that behavior but on

the other side are there genes the

nature side is there something that

drives Behavior well that's what we're

going to talk about in this chapter uh

primarily but you'll see in a little bit

that this nature versus nurture

debate might not be as valid as we once

thought it

was so how can we study the impact of

genetics versus environment on criminal

Behavior take a second to think about

that what could we

do

well we could look at DNA and we've had

the ability to do that since the 90s but

how about before that is there any way

that you can think of that we could

study the impact of genes versus

environment if you really think about it

your DNA every cell in your body has

your complete set of genetic

code there you can see the DNA Helix

that makes you what you are who you

are there's the DNA Helix

there but we haven't had the ability to

read your genetic code for that long and

you know what frankly that's pretty

expensive and we could identify specific

genes but there's something more to this

what if we looked at twins not these

kind of twins I you might be too young

to remember that movie it wasn't a very

good movie but more like these kind of

twins Mary Kate and Ashley there they're

identical twins so theoretically they're

basically like clones of each other they

start off with the same

DNA so what if we could take identical

twins or monozygotic Twins and compare

them to fraternal twins or dizygotic

Twins and we look at their behavior now

researchers have been doing this in the

field of psychology and medicine for

years and years and years so if you have

an identical twin that has let's say

schizophrenia you have roughly about a

50% % chance of having schizophrenia

yourself one of my favorite disorders

ADHD is one of the most highly heritable

disorders and if your identical twin has

ADHD you have about a 75% chance of

having

ADHD now the fraternal twins it's far

less so what that does is it gives us an

IDE aide as to the impact of those

specific genes because you have your

identical twin you have your fraternal

twin and theoretically you're raised in

the same environment now these two look

different but they look similar enough

and I would hope that their parents

would treat them roughly the same in

their

classmates but genetically they're very

different over here genetically

identical

so I just to review this identical

twins start from one fertilized

egg okay they're a single zygote that

divides into two mono zygotic twins or

identical twins so this is the same DNA

the DNA here in these two cells is

identical but these two cells later

develop into two

people now fraternal twins or dizygotic

twins here you have two

eggs two fertilized

eggs so they have

similar but not identical genetic

material now I don't know too many twins

and if I really think about it I guess I

knew one set of identical twins growing

up and they were they were pretty pretty

similar however you could definitely

tell them apart I mean they looked a lot

alike once you got to know them though

they were they were a little different

why is that think about the twins that

you know the identical twins are they

really

identical okay so we have these

identical twins and we like to think

that the mother here and the father

who's probably off watching TV somewhere

uh is going to treat these children the

same so they're going to have a shared

environment and they have shared

genetics in contrast to the fraternal

twins that would have totally shared

environment but then different genetics

and what we can do then is come up with

Concordance rates so that's a percent of

monozygotic versus dizygotic twins so

you can see the

impact of the

genetics in contrast to the impact of

the

environment all right this is a little

hard to see here sorry about this but

this says although identical twins step

and Robert Bruce spolski were both

Killers each acted alone unaware of the

other's homicidal

tendencies in prison Steven was quoted

as saying I thought I was the only

murderer in the

family what if we took

criminals like

twins and we could find sets of

monozygotic versus dizygotic Twins and

look at the impact of the genes there so

you would identify sets of twins and

then look at criminal

Behavior so you would find one twin

that's a murderer and then you see if

the other one is as

well and both the monozygotic and D

zygotic

Pairs and you would hope that the

monozygotic would have a much higher

concordance rate that would show you the

impact of the genetics so I mean I don't

really think anybody's done this study

but we could do a large prison study

where we

identify uh one pair of uh twins that is

currently incarcerated and then we would

locate the other twin and figure out if

they had a similar criminal back

background that's how that study would

be done or that research would be

done now there's something else that we

could do um and this is a little

different uh Gerald Levi here and Mark

Newman you can see that those guys look

kind of

similar they're identical twins and I I

just want you to note though that look

at Mark here same jeans Mark is

significantly heavier exact same jeans

different weight so this isn't perfect

but what's unique about these two is

that they were separated at

Birth

so they were put up for

adoption and they were adopted to

different families now they stayed in

roughly the same area but look at these

two and I don't know if they really

looked this similar before they met each

other but they have a lot of striking

personality characteristics in fact they

both are

firefighters and that's how they

realized that they were identical twins

because a fellow firefighter said hey

you look just like this guy that's a

firefighter 60 Mi up the road they met

each other and realized that hey I'm

adopted you're adopted and they figured

out that they had this shared

history so researchers in the area of

Personality have been doing this work

for a long time if you've taken

personality psychology there's a good

chance that you've seen pictures of

these two guys cuz they're pretty pretty

famous okay but but but but there's a

problem here and that we think that

identical twins have identical

DNA do

they well I don't quite think so now

there's one weird thing there's uh

dionic and

monochorionic uh monozygotic Twins and

so that's like a single placenta versus

a uh two placentas so that's the first

thing

so that uh prenatal environment might

actually be

different now there's something else

it's far more relevant here and these

are called epigenetic factors and here

what happens is that your environment

impacts your genes like you have this

huge genome but it is not

always like on okay so genes are

expressed they're either turned off or

they're turned on genes typically code

for proteins proteins are the building

blocks of life everything in your body

is made up of proteins and the genes are

the the plans for those

proteins okay

so what happens well your environment

signals your genes when to turn on and

when to turn off that's called this

field of study is called

epigenetics okay so I know this example

sounds really bad but uh I use it

frequently and um you know in Florida in

South Florida there's a large uh

homeless

population and when you look at the feet

of the homeless in Florida frequently

they don't wear shoes

so what do their feet look like and I

know this sounds like

politically uh incorrect but it's a good

example so those individuals that walk

around Barefoot I guess I mean there's

lots of people that walk around Barefoot

all the time they don't have to be

homeless but their feet get really

really

thick so they have

genes that react to the environment that

change the thickness of their feet had

they been wearing nice comfy shoes and

taking care of their feet their feet

wouldn't look like that but they have

the genetic

material uh to respond to the

environment like that you have that too

um if you play guitar you might have

calluses on your fingers the body is

going to change in response to the

environment that's epigenetics so even

though you have this genome and you have

a twin that has the exact same genes any

sort of environmental differences are

going to affect how those genes are

expressed so even though you have

identical genes it's not like you're

really

identical and ah again sorry this is

kind of hard to read but this is a quote

and this is uh similar quotes in your

book here in reviewing both twin and

adoption studies research suggests that

genetics contributes moderately to

criminal Behavior more so with

nonviolent crime however environmental

factors are also very important and

that's from ad Adrien rain in a

literature review of all these studies

and there's been over a hundred studies

like this in this area but you know what

like it's really difficult to draw

conclusions from this

um and the major thing that you need to

take out of this is that nature versus

nurtured debate is dead it's over so if

someone ever asks you you know is that

like nature or

nurture um let's say schizophrenia you

always always always always say well

it's a little bit of Nature and a little

bit of nurture so I like to think it of

it as uh nature via nurture so you you

will have genetic predispositions to

things but environmental factors have to

come in in order to see the expression

of those genes

okay now there's other factors that this

uh chapter goes into psychophysiology a

little bit so I'm sure you've heard oh

criminals are fearless they don't

respond to fear the same way that

non-criminals do into some degree that's

that's correct so their nervous system

does seem to respond a little different

uh maybe you'll recognize this guy this

is Travis Pastrana um there he's doing a

double back flip on a motocross bike he

seems to be totally

Fearless why is that is there something

different with his genetics or his

biology

psychophysiology yeah actually there

probably is and you may have seen this

before and we we have talked about this

earlier in the class that's an old

polygraph and what the polygraph

measures is your physiological reactions

and when they hook people up to

Machinery that measures physiological

reactions and show them graphic images

people that are violent or antisocial

don't respond quite the same now does

that mean that that causes the criminal

Behavior no no no no no no no we can't

say it's causitive it's a correlate to

the criminal Behavior so it's like the

Chicken and the Egg which came first we

don't know but they're

related now what might that be and

usually what you see is lower levels of

arousal in antisocial or Psychopaths or

murderers lower levels of physiological

arousal well we'll talk about that in

just a second but the first thing that I

want to talk about is temperament so

your temperament is like your

disposition how you are think about

this uh with little kids or babies

what's their temperament like and you'll

hear parents say oh you know Susie is

such a good baby she's so easy to take

care of she never

cries and then other parents will say oh

my God this kid is a nightmare he's up

all night crying you may have heard of

uh Kaki

babies so what is cic and it's different

in horses I mean in horses it's a

different thing in

babies what is colic now I've heard many

of doctors say well the treatment for

colic what you do is you take a vacuum

cleaner and you put it in the baby's

room when they're all upset you turn the

vacuum cleaner on that soothes the baby

so they'll go to sleep uh the funny

thing is that the doctors might say that

but what that really does is it drowns

out the crying so the parents don't hear

it so they can go to sleep that's that

kid's temperament it's their disposition

and your temperament is really stable

throughout your entire life so if you

are a cranky baby you're going to be a

cranky adolescent teenager and

adult and there are other factors like

prenatal factors

so there might be birth

complications exposure to toxins like

nicotine alcohol drug

exposure uh alcohol exposure can lead to

fetal alcohol syndrome although it's a

lot less rare than we thought and

there's some evidence that shows

nicotine alcohol and drug exposure being

correlated with ADHD but the research

isn't great there so there might be

prenatal factors like that that lead to

later

uh criminal

behavior and then there's going to be

neurological factors we're going to talk

a little bit about the frontal loes um

and the amydala we'll talk about in

later chapters same with hormones

neurotransmitters and then disorders

like epilepsy could those be the root of

criminal

Behavior well one famous case that I'd

like to bring up and the book talks

about briefly is Phineas gauge so I'm

sure you've heard of Phineas gauge every

introductory introduction to psychology

class should cover Phineas gaug but he

worked on a railroad and uh what he was

doing is constructing the railroad and

so they had to like blast a lot of rock

and what they would do is they would

drill a hole into the ground and then

they' put some Dynamite or explosive

down there and then put some sand on top

of it with their little Wick and then

they would take a rod and they would

pack it down in the hole that Rod was

called a tamping rod and so fineas Gage

was a really good worker hard worker

nice guy went to church uh saved his

money and one day as he was using that

tamping Rod he was leaning over the rod

and something happened probably a spark

ignited the dynamite and it shot the rod

up through the hole like a bullet and it

went right

through his eye here and then up through

the top of his head this is actually a

picture of Phineas Gage this is a real

guy and you can see he wasn't that

disfigured I mean he lost an eye and

maybe the way people treated him

afterwards contributed to his behavior

but more importantly he lost a good

chunk of his brain in the accident now

after this thing went up through his

head he stood up he could walk around he

got some help he survived I mean he was

just fine but a good chunk of his brain

was taken out now he probably should

have died and he did have a near-death

experience so you got that but you can

see the path of this tamping rod and it

basically took out his frontal

loes

and we have seen a pattern of behavior

in many many patients that have similar

injuries in fact if you get a frontal

lobe injury you'll probably have similar

behavior and what we call the skills

that the frontal lobe are responsible

for are uh executive functioning skills

so like executive like an executive in a

company those skills that you need to

plan out your life so it's thinking

ahead in the future planning stuff like

that Phineas lost that and his

personality also

changed that's the actual tamping Rod

right there they found these photographs

in like 2010 they thought this was like

a photograph of a whaler and this was a

harpoon but it's not that's Phineas and

that's a tamping rod and he traveled

around after his injury he took the rod

with him he traveled all over North

America and South America and he lived a

pretty functional life but the legend is

that Phineas was or uh Gage was no

longer Gage was a quote from one of his

co-workers so he became a little more

unruly he would

swear um he was uh quicker to anger uh

his work record wasn't as good he

probably stopped going to church he

changed and when people have frontal Lo

injuries they become far more impulsive

and a lot of times they get into trouble

so maybe it's dysfunction with the

frontal loes we'll talk about that more

the next person that I want to talk

about is Hans ICN

and there he is right there and the book

goes into far more detail about this um

I want to talk about this briefly so we

have introversion over here and

extroversion over here now I

think had this is like a on a scale so

on one end you have introverted people

and on the other end you have

extroverted people and what he said was

that this is all about

central nervous system arousal so

remember go back that picture of uh

Travis Pastrana on the motorcycle or

that little kid on the skateboard at the

top of the hill what does that mean in

terms of iyn theory

well introverted people he said have a

lot of central nervous system

arousal and so any type of stimulus

pushes them way over the edge they don't

like like it so they're introverted they

don't seek out exciting activities they

stay within themselves they you know

they don't go outside they don't

interact with friends they're

introverted and here are some of the

character traits that are associated

with people that are introverted

unsociable quiet passive careful that

kind of makes sense now let's think

about somebody that's all the way on the

other end somebody that's

extroverted if you don't know who Travis

Pastrana is think of like a daredevil

like uh evil coneval or

something so I think said the

extroverted people had very low levels

of central nervous system

arousal that's why they're extroverted

because they need to get their arousal

level up so they go out they're active

they socialize with other people they do

exciting things because they need that

level

of um central nervous system arousal to

go up so think about that now I used to

do an experiment in my classes where I

would take um those extreme lemon sour

uh heads I don't know what they're

called uh Atomic Warheads I think

they're called and I would give them to

students and I gave them a measure of

introversion versus

extroversion and so we would figure out

who the introverted students were and

then the extroverted students then I

would give them this really sour candy

and then have them measure the amount of

spit that was produced in response to

the candy now this that's like central

nervous system arousal and the idea is

that introverted people who already have

a high level of arousal will respond a

lot more and they're not going to find

that situation pleasurable so they're

going to produce a lot more saliva

whereas extroverted people have that low

level of central nervous system arousal

they eat that candy and it's just a

little tiny bump up now we never did

statistical analysis but that research

study was done a long long time ago and

I was trying to replicate that and they

show that that is in fact correct now if

we took an introverted person and showed

them pictures of a violent crime scene

and then measured heart rate respiration

uh sweating on their skin or galonic

skin response the introverted person's

responses should go way

up whereas the extroverted person

they'll just have like a little tiny

response and so maybe it's this

extraversion that has something to do

with criminal Behavior because somebody

that's really introverted probably isn't

going to be committing crimes over here

they might just do it to get excited now

stability versus unstability or I think

talked about uh

eroticism

versus um like stability and then he

talks about psychoticism as well so like

uh that's like a psychopath or callous

unemotional Behavior which receives a

lot of attention right now in the

research but let's just look at this

emotional stability here so over here

would be the neuroticism or emotionally

unstable and stable down here so let's

say somebody's extroverted and they're

really emotionally stable it might be

talkative responsive easygoing or

Lively however if you look at somebody

that is emotionally unstable and

extroverted over here you're going to

see Restless aggressive

excitable changeable

impulsive these personality

characteristics over

here kind of remind me of personality

characteristics of criminal behavior and

then read about psychoticism as well

which has received less attention than

these other two factors however it's a

pretty provocative idea and I thinks

ideas really could explain a lot of

criminal Behavior so again do not

neglect your textbook make sure you read

this because the text goes into detail

about all the studies and it has far

more information than these

screencasts um these screencasts are

just uh uh hopefully I can add to the

text

material and uh help you engage in the

material more so if you have any

questions please let me know next week

uh we will continue with uh the

psychopath which is probably my favorite

topic and we have some videos to watch

too so again contact me if you have any

questions