PSYCHOBIOLOGICAL CRIMINOLOGY
Biology may not be destiny, but it provides limits to the practical. (Eric Palmer)

    Biology, or at least some of the key principles of it (structure determines function; anatomy is destiny) has had an enormous impact on criminology.  It's the perfect (and most common) field to draw from, for any field, in fact, to become interdisciplinary.  Sociology has even drawn upon it (with the fields of sociobiology and biosocial criminology), but psychology mixed with biology (psychobiology) has made the most inroads.  Psychobiological criminology also overlaps with constitutionalism and mental deficiency theory, and to be sure, no purely biological theories of crime exist.  Criminologists tend to refer to biological insights as "factors", and some criminologists even water down the dependent variable to say that instead of explaining crime, they are explaining maladaptive behavior patterns. 

    One of the first things you'll notice about psychobiological criminology is its inordinate concern for violent, aggressive crime.  Many critics argue that the field ought to focus more on property crime (since some research shows a stronger genetic link with this type of crime).  However, the fact remains that violent arousal is one of the most well-documented areas of biology.  Not only are there certain organs inside the body that produce aggression, but aggressive stimuli outside the body will trigger bodily reactions producing a "neurological high".

HORMONES

    Hormones are chemical messengers produced by the endocrine glands, the brain, gastrointestinal organs, sex organs, the kidney, the heart, the pineal gland, the skin and the hair.  They exert a strong influence on behavior, principally by inducing brain events that prompt people to behave in certain ways to environmental stimuli.  Hormones not only influence reactive or conscious behavior after environmental cues, but they also influence anticipatory or unconscious behavior (by knowing what the body needs beforehand, hormones make a person think they want something before they see it).

    Biologists separate them into two classes: peptide hormones, which act on cell membranes; and steroid hormones, which act on cell nuclei.  The effects of peptide hormones are fast while the effects of steroid hormones are slow.  When a hormone is released in the brain (usually a peptide), it's called a neuropeptide. Hormones that are released elsewhere in the human body are referred to as activating in the periphery.  Hormones are fluids, "secretions" really, that you might compare to sweat, the fluid "secreted" by the skin.  The body, as you know, is mostly fluid, and hormone secretion is intimately involved with and limited by the need for fluid homeostasis and sodium maintenance.  In addition to the whole body's need for homeostasis, the endocrine system itself maintains a state of endocrine homeostasis, regulated by the hypothalamus, arguably the most important region in the brain.  Every form of life except one-celled organisms have a hypothalamus, and it regulates a number of biological clocks: circadian rhythms (sleep, diurnal, nocturnal activities), running activity (e.g. in hamsters), reproduction, menstruation, rapid-eye-movement, attention span, food preferences, migration, hibernation, and singing behavior (in nonhumans), and seasonal affective disorder (melancholy).  In addition, the hypothalamus is located within the limbic system of the brain, controlling the Autonomic Nervous System (involuntary functions).  The limbic system is one of the most unmapped areas of the brain. It has been called the "crocodile" brain. One study found that 15 of 15 death row inmates had some kind of lobe dysfunction in their limbic system.

    The key concept of endocrinology is central motive state.  In psychology, the equivalent concept is desire.  Some simple examples are thirst, hunger, and sex, and more complicated pathways or "circuits" exist for various other states of excitation, arousal, or quiescence.  Hormonal reactions also don't occur in a vacuum.  Desires have an appetitive (searching) phase and a consummatory (fulfilling) phase. Although individuals by themselves can probably generate the appetitive phase of a hormonal reaction, they need the hormonal reactions of others (pheromones) or additional environmental stimuli to generate the consummatory phase.

    The criminological study of glands has been around since 1928 with the publication of Schlapp and Smith's The New Criminology (not to be confused with a book in radical criminology by the same name in the 1970s).  Schlapp and Smith argued that criminals were two to three times more likely to have glandular disorders.  Of course, there are many glandular disorders that have nothing to do with crime, but some of the ones that there has been speculation about include hyperthyroidism (which causes personality change) and Cushing's disease (which often manifests abnormally compulsive and obsessive behavior). Both diseases predominantly affect the female population, however.  Males are more likely to suffer from brain disorders, such as stuttering and dyslexia.  Males are also usually right-brain dominant, which explains why left-handedness usually occurs one and half times more often in men as well as their greater spatial (exploratory) abilities.

    Testosterone, and other androgens, are probably the most important hormones in criminology.  Testosterone has been related to aggressive criminal behavior in a number of studies, almost as many as those linking crime to the female menstrual cycle.  It is believed that high levels of testosterone reduce a person's social integration, making them more of a loner, and freeing them up to deviate from society's norms.  Female menstrual cycles have been linked to irritability, aggression, and a patterned increase in hostility.  Some 70% of women in prison claim to have committed their crimes while experiencing PMS (53% before menstruation; 17% during).  Androgens are basically masculinizing hormones.  Women normally have one-tenth as much testosterone as men.  Too much androgen in the mother's body during pregnancy and birth is associated with aggressive behavior in children.  Unfortunately, many of the anesthetic, childbirth-easing drugs given to women are androgen-based substances.  In men, testosterone levels peak in the mid-teens, and sometimes lead to precocious sexuality (testosterone has this effect in early-teenage women too).  The levels decline over the life course.  Testosterone is highest in the morning right after waking up and decreases throughout the course of the day.  It is also highest during the months of November and December, at least for men.

    Speaking of seasonality, there are a number of seasonal disorders which may or may not be hormone-related.  Seasonal Affective Disorder (SAD), or "winter depression" has been known about the longest and is possibly linked to melatonin, a sleep-related hormone secreted by the pineal gland in the brain.  Dr. Cliff Arnall, a UK psychologist, has dubbed January 24 "the most depressing day of the year" and has also devised a formula for calculating when a person's lowest point in the year occurs.  His theory, or model, is as follows:

[W + (D-d)] x TQ
M x NA

    The equation is broken down into seven variables: (W) weather, (D) debt, (d) monthly salary, (T) time since Christmas, (Q) time since failed quit attempt, (M) low motivational levels and (NA) the need to take action.

NEUROTRANSMITTERS

    Neurotransmitters are chemicals that allow for the transmission of electrical impulses in the brain and are the brain's way of processing information.  They are not normally involved with the autonomic (regulatory) nervous system (as hormones are, although some glands trigger neurotransmitters, or neuropeptides, as well as hormones), but with the Central Nervous System and higher-order cognitive functioning. As such, they have become of great interest to criminologists who study things like antisocial personality and psychopathy which are believed to manifest brain systems with neurotransmitter levels "out of balance".  It's well documented that alcoholism and drug dependence are associated with differences in neurotransmitter levels.  In fact, the biggest research problem in studying neurotransmitters is finding criminal research subjects who aren't already "self-medicated" on alcohol or drugs.  Although a person's normal neurotransmitter levels are determined genetically at birth, it is quite easy to manipulate them with drugs (medications for the mentally ill, stop-smoking pills), with diet (sugar, caffeine, chocolate, food additives), with stress (stressful environmental conditions), and with altitude (hypoxia is a condition mimicking the effect of neurotransmitter imbalance at altitudes above 3,800 feet above sea level).

    There's not that many neurotransmitters in the central nervous system (see table for complete list), and the three most commonly studied ones are serotonin, dopamine, and norepinephrine. Antisocial people have significantly lower levels of serotonin than ordinary people.  Schizophrenics have significantly lower levels of dopamine, and cocaine addicts have higher levels of dopamine.  Levels of norepinephrine have also been associated with antisocial behavior.  Perhaps a look at the table at this point would be instructive.

    Serotonin is probably the most important neurotransmitter in criminology. As stated previously, antisocial people have lower levels of serotonin.  This may be either genetic or environmental, because neurotransmitter balances are constantly changing as memories are stored in the brain.  Every new memory permanently changes the neural pathway structure, thus creating the opportunities for neurotransmitter imbalances.  People who are genetically endowed with lower serotonin levels ("born antisocials") may therefore "grow out of it", and likewise, someone who is born with normal serotonin levels may develop an antisocial personality (what is called "reduced serotonergic activity" or a "serotonin uptake problem").  Reduced serotonic activity and crime is one of the strongest connections in biopsychological criminology.

    Brain wave activity has been studied, and the general finding is that criminals have slower brain waves, i.e., slower EEG activity.  Whether this is an indicator of a central or autonomic nervous system problem depends upon the researcher.  The work of criminologist Hans Eysenck points at one of the reasons for why criminals can beat the lie detector is because their slower autonomic nervous system results in their not being easily stimulated, hence they seek out exciting, criminal behavior in a "stimulus hunger".  Mednick, a sociobiologist, points out that criminals have a lower rate of  skin conductance response (SCR), the time it takes the skin to conduct electrical current.  He argues that this affects the ability of criminals to benefit from negative reinforcement, and since fear is the most powerful reinforcer known to psychology, criminals experience no fear or anxiety.  Lobe dysfunction, which can occur with head injury or birth trauma, also has been studied in criminals.  Prisoners often report having had a head injury involving loss of consciousness, and 80% of violent criminals had greater than average birth complications.  There's evidence to suggest that frontal lobe dysfunction may characterize violent offenders while temporal lobe dysfunction may characterize sex offenders.  Research involving newer imaging techniques (MRI, CT, PET, SPECT) is ongoing.

VITAMINS AND DRUGS

    Vitamin deficiencies and/or dependencies (as well as food allergies, eating disorders, and cholesterol levels) have been implicated in crime.  Vitamin B3 and especially B6 deficiencies and/or dependencies have been found in 70% of criminals as well as alcoholics and the mentally ill.  There is a difference between a vitamin deficiency and a vitamin dependency. Vitamin deficiencies cause low IQ, mental impairments, and weak immune systems.  In some Third World countries, vitamin food supplements are almost unheard of, and the lack of vitamin A (as well as Zinc), for example, causes almost as many deaths as the poverty diseases of malaria and cholera [see chart below].

    Vitamin dependences work differently.  For one thing, a person has to have a genetic disorder in order to have a vitamin dependency.  There would have to be an inborn error in metabolism, and such a person would normally report stomach aches when eating certain kinds of food.  A vitamin dependency works in the same way as toxicity or overdose.  Some people die, others become sick and start vomiting, but most (who don't know they have a dependency) get headaches and become irritable.  Regarding toxins, one of the things the body definitely does not need is lead.  The human body has a fixed lead burden, as well as a low tolerance for other toxins and minerals.  Cadmium, one such toxin, is an invisible gas given off by welding.  If you trace the occupational history of many mass murderers and violent criminals, you'd be surprised at the number who were welders at one time or another.  Almost all the effects of vitamin, food, toxin, and mineral factors are referred to as producing "transient states" of criminality.

    Certain drugs, typically bought at a pharmacy (with or without prescription), and even some illegal drugs, may have a connection with regulating criminal behavior.  I'm going to avoid the whole "drugs cause crime" (enslavement v. escalation) arguments, and jump right into the potential of creative pharmacology for crime prevention and criminal rehabilitation from this point on.... (but first, some dead ends)

    First of all, smoking cigarettes is a bad thing. Nicotine operates as a MAO inhibitor, and is associated with Parkinson's Disease and a high prevalence of the more dangerous psychiatric disorders and serious substance abuse.  About 25% of pregnant women smoke and run the risk of their children having hypoxia-induced brain damage.  Smoking alters synaptic pathways in ways that are largely unknown.  The drug Bupropion (Wellbutrin; trade name: Zyban) would not only be a good smoking cessation tool, but it would retard depression and perhaps help with other mania-type conditions.

    Alcohol is another deadend, like marijuana, cocaine, LSD, and the opiates.  It alters the functions and communication between the liver, the brain, and other vital organs.  When BAC increases, it activates the reward centers of the brain so that the simplest behavior is experienced as rewarding.  When BAC decreases, there's a depressive effect.  Some drugs are neurotoxic.

    MAO (Monoamine Oxidase) inhibitors (complex polypeptides) cause a rise of norepinephrine, dopamine and serotonin, producing a sense of calm and serenity in a person, and making them much more amenable to therapy and treatment. Avoidance of cheese, red meat, and sausage (in short, a vegetarian diet) will produce the same effect as taking an MAO inhibitor.

    SSRI (Selective Serotonin Reuptake Inhibitors) are a new set of drugs designed to replace the tricyclic antidepressants.  They powerfully inhibit serotonin reuptake, and are extremely effective in treating obsessional and mood disorders, particularly impulsiveness and sensation seeking.  They also reverse sexual dysfunction; Viagra is an SSRI.  One could emulate the effects of an SSRI by taking Yohimbine, Ginseng, or Ginkgo.  Hypericum, which is the active ingredient in St. John'sWort also has mood-elevating effects. There's some initial speculation that SSRIs could decrease tendencies toward aggressive, criminal behavior (see this article).

    The unpredictable anesthetic GHB (gamma-hydoxybutyric acid), which is a precursor of the neurotransmitter GABA, holds rehabilitative promise.  It produces a touchy-feely sensation (similar to the illegal drug Ecstacy), a sense of serenity, feelings of emotional warmth, and the desire to socialize.  It operates by inhibiting dopamine release to brighten mood and sharpen mental focus. It's effects can be emulated by the amnestic, date-rape benzodiazepine drug, flunitrazepam, better known as the hypnotic "forget pill", Rohypnol.

INTERNET RESOURCES
Biopsychiatry.com's Drug Guide
Biocriminology Newsletter
Human Illnesses, Diseases and Conditions
Index of Biology-related sites

PRINTED RESOURCES
Booth, A. & W. Osgood. (1993). "The Influence of Testosterone on Deviance" Criminology 31(1): 93-117.
Brain, P. (1993). "Hormonal Aspects of Aggression and Violence" pp. 173-244 in A. Reiss & J. Roth (eds.) Understanding and Preventing Violence. Washington DC: National Academy Press.
Fishbein, D. (1990). "Biological Perspectives in Criminology" Criminology 28(1): 27-72.
Kramer, P. (1994). Listening to Prozac. London: Fourth Estate.
Norris, D. (1997). Vertebrate Endocrinology. San Diego: Academic Press.
Scerbo, A. & A. Raine. (1992). "Neurotransmitters and Antisocial Behavior" in A. Raine (ed.) The Psychopathy of Crime.
Schulkin, J. (1999). The Neuroendocrine Regulation of Behavior. NY: Cambridge Univ. Press.
Vold, G., T. Bernard & J. Snipes. (1998). Theoretical Criminology. NY: Oxford Univ. Press.

Last updated: Nov 30, 2006
Not an official webpage of APSU, copyright restrictions apply, see Megalinks in Criminal Justice
O'Connor, T.  (Date of Last Update at bottom of page). In Part of web cited (Windows name for file at top of browser), MegaLinks in Criminal Justice. Retrieved from http://www.apsu.edu/oconnort/rest of URL accessed on today's date.