0:01 despite being very popular in the early
0:04 20th century biological explanations of
0:06 crime fell out of favor entirely for
0:08 several decades after world war ii
0:09 following the revelations of the
0:12 holocaust and the role that those early
0:13 theories played in it i have other
0:15 videos exploring that in greater depth
0:17 which you can check out there are links
0:18 in the description below during this
0:20 time little serious consideration was
0:22 given to biological factors in trying to
0:24 understand human nature and it wasn't
0:27 until the 1970s that biological factors
0:28 started to be taken seriously again but
0:30 this time with a clear rejection of
0:33 biological determinism in other words
0:35 biological factors were not considered
0:36 to be the sole cause of criminal
0:39 behavior instead these modern biological
0:41 theories argue that each individual is
0:43 unique and there is no one universal
0:45 explanation for criminality often
0:48 referred to as biosocial theories they
0:50 recognize that while biological factors
0:53 can predispose someone toward engaging
0:56 in criminal or anti-social behavior the
0:58 social environment is also a necessary
1:00 component so according to biosocial
1:02 theories in the debate over nature
1:05 versus nurture the answer is simple both
1:07 play an important role and the question
1:09 then becomes identifying the extent of
1:11 the relative influences of different
1:14 biological and social or environmental
1:15 factors so let's take a look at some of
1:18 these biosocial theories which generally
1:20 can be divided into four major areas
1:22 genetics biochemical
1:29 to build off of the early biological
1:31 theories let's start with genetics the
1:33 idea is that genetics shape how we
1:35 interpret our environment and learn
1:37 socially we inherit predispositions to
1:39 certain behaviors these behaviors are
1:42 more likely to occur given the right set
1:44 of social or environmental circumstances
1:45 this includes criminal behaviors the
1:48 research on genetic influences on crime
1:49 particularly look for similarities
1:51 between parents and children and also
1:53 among siblings a child who has parents
1:56 or siblings particularly siblings of the
1:58 same sex that are involved in crime are
2:00 more likely to engage in crime
2:02 themselves studies comparing the
2:04 criminal records of twins have found
2:06 greater patterns of criminality among
2:08 identical twins those who share the same
2:11 identical genetic makeup as opposed to
2:13 fraternal twins and studies of boys
2:15 adopted at birth have found the highest
2:18 rates of arrest among boys with both
2:20 adoptive and biological fathers with
2:22 criminal histories and the lowest rates
2:24 were among those with biological or
2:26 adoptive fathers who had no criminal
2:28 histories so this indicates that there
2:30 is likely a genetic influence here but
2:32 there is much we don't know about the
2:34 nature of this relationship just because
2:36 two things are found to be related does
2:37 not mean we know exactly how they're
2:39 related it doesn't mean that one causes
2:42 the other and we don't know exactly what
2:43 may have been inherited that relates to
2:46 criminality is it genetics
2:48 neurophysiology temperament or something
2:51 else or are there environmental factors
2:52 that may explain the correlation
2:54 prenatal care nutrition environmental
2:57 toxins susceptibility to alcohol or drug
2:59 addiction and many other potential factors
3:03 speaking of which this points to the
3:05 next set of biosocial theories that
3:07 argue crime and especially seemingly
3:09 irrational violence is a function of
3:12 biochemical imbalances that negatively
3:13 influence behavior the research on these
3:16 theories primarily focuses on diet
3:18 hormones allergies and environmental
3:20 contaminants such as lead intake what we
3:22 eat or don't eat can certainly influence
3:24 our behavior an over or under supply of
3:26 certain chemicals and minerals can lead
3:28 to psychological imbalances if we eat a
3:30 bunch of junk we're not gonna feel as
3:33 well such as having too much sugar or
3:35 too many high carb foods not eating can
3:37 also impact our behavior i myself am
3:39 certainly guilty of being hangry after i
3:41 haven't gotten food in a while something
3:43 that my friends and family members can
3:44 certainly attest to if we eat foods that
3:46 are good nutritious filling we're going
3:48 to feel better and ultimately behave
3:50 better another factor is hormonal
3:52 influences hormones can cause areas of
3:54 the brain to become less sensitive to
3:56 environmental stimuli things happening
3:57 in the environment that register in the
3:59 brain decreasing levels of hormones as
4:01 men get older is one theory for
4:03 declining crime rates over the life
4:06 course environmental contaminants lead
4:08 being the most obvious also copper
4:11 cadmium mercury and inorganic gases that
4:13 can all cause emotional and behavioral
4:15 disorders illnesses and even death lead
4:17 exposure is a particular concern
4:19 especially with its long-term effects on
4:21 childhood development in fact the
4:23 concentrated effort to eliminate
4:26 exposure to leads since the 1970s is one
4:28 prominent theory for why crime rates
4:35 another set of biosocial theories are
4:37 neurophysiological looking at how the
4:39 brain functions with the idea that
4:41 impairments of executive brain
4:43 functioning can lead to increased
4:45 impulsive and aggressive behavior thus
4:46 increasing the risk of engaging in
4:48 criminal behavior this could come in
4:50 many different forms one is brain structure
4:52 structure
4:54 not quite like that no no no we're all
4:57 done with that now tumors legions
4:59 injuries disease can all cause damage to
5:01 the brain itself leading to a greater
5:03 risk of depression irritability temper
5:06 outbursts and violent attacks some
5:08 studies looking at eeg readings of
5:10 electrical impulses given off by the
5:12 brain have recorded much higher levels
5:14 of abnormal readings indicating brain
5:17 dysfunction among violent criminals
5:18 another is brain chemistry which looks
5:20 at abnormal levels of certain
5:22 neurotransmitters in the brain such as
5:24 dopamine and serotonin which have been
5:27 linked to impulsivity hyperactivity lack
5:29 of attention and sensation and thrill
5:30 seeking for similar reasons some
5:32 research has also shown links between
5:34 criminality and attention deficit
5:37 hyperactivity disorder adhd the arousal
5:39 theory argues that some people's brains
5:41 respond differently to environmental
5:43 stimuli and the need for greater levels
5:46 of stimulation and sensation can lead
5:49 them toward riskier thrill-fulfilling
5:51 behaviors including crime and violence
5:53 so it's likely that all these factors
5:54 are closely related looking at the same
5:56 problem through different lenses and
5:58 it's difficult to break apart how much
6:00 influence each one has i have other
6:02 videos on different psychological
6:03 theories that explore some of these
6:05 connections further there's a link in
6:06 the description below you can check that out
6:11 and the final area of biosocial theories
6:13 is evolutionary theory the major premise
6:15 of evolutionary theory is that adaptive
6:17 traits became ingrained as humans
6:19 evolved because they were necessary for
6:21 survival especially when competing for
6:23 scarce resources this includes traits
6:25 that promote more aggressive and
6:27 impulsive behavior and this is one of
6:29 the explanations for the differences and
6:31 crime patterns between males and females
6:33 especially violent crime and while these
6:35 traits were highly adaptive in the past
6:37 and are still certainly necessary today
6:40 to an extent they don't fit in as well
6:42 in our modern society especially higher
6:44 levels of aggressiveness and impulsivity
6:46 and this predisposes some men toward
6:52 so that's just a brief overview of some
6:53 of the modern biosocial theories of
6:55 crime there's a lot more to go over but
6:56 that's just the broad strokes there's
6:58 certainly sufficient evidence to
7:00 indicate there may be a biological
7:02 influence on criminal behavior but none
7:03 of these biosocial theories are
7:06 definitive some have more support than
7:07 others and they've been subjected to
7:10 only limited testing mostly in clinical
7:12 settings with small sample sizes so
7:14 there's much we really don't know but
7:16 this body of research continues to grow
7:18 and if there is indeed a biological
7:20 influence on criminality it's important
7:22 to remember that it merely predisposes
7:25 some individuals to an increased risk of
7:26 potential criminal behavior it takes the
7:28 right combination of influences in the
7:30 social environment to actually trigger
7:32 that predisposition which is something
7:33 that we're still trying to get a handle on
7:34 on
7:36 much left to learn you can check out my
7:38 other videos on early biological
7:40 explanations of crime including the
7:42 negative impacts that they had as well
7:43 as psychological theories there'll be
7:45 links on the screen and the description
7:47 below and until next time thank you for
