Announcements

Final 8:00, Friday, May 11.(A-L here; M-Z 100 MSEB)

Predictions:

females

males

Women prefer less masculine male faces (and men prefer more masculine faces in women) for long term relationships under conditions of environmental harshness.

Consistent with idea that high-quality partners may be low investors and suggests that under harsh ecological conditions, men and women prefer a low quality / high investment partner for long term relationships.

Behavior and relatedness

Like many animals, social groups in humans are often made up of related individuals.

Behavior and relatedness

Behavioral Syndromes

correlation of behavior across multiple contexts

for example, aggression (territorial disputes vs. mating)

Same as personality in humans?

Growing consensus that many descriptors of personality can be characterized into five broad underlying dimensions of personality (The Big Five Model – John, 1990)

The nature of personality

Extraversion assertive, energetic, quiet, shy, withdrawn sociable

Neuroticism anxious, emotional, calm, at ease, unemotional moody

Conscientiousness dependable, organized, careless, irresponsiblepractical frivolous

Agreeableness cooperative, generous, cold, quarrelsome, selfish warm

Openness curious, imaginative, shallow, simple insightful

High score Low score

Tendency to be engaged

Tendency toward neg.moods

Tendency to plan & conform

Tend to cooperate

Tend toward diversity

The nature of personality

Extraversion extroverted introverted

Neuroticism nervous, high-strung calm, relaxed

Conscientiousness conscientious disorganized

Agreeableness agreeable disagreeable

Openness open to new experiences close-minded

High score Low score

Take the Big Five test:http://www.outofservice.com/bigfive/

• Assessment of individual differences on these 5 dimensions can be determined reliably by self-report

• Personality is predictive of a wide range of social and work-related behavior and some behavioral pathology, personality can be an independent risk factor for mental health problems

– Individuals who are impulsive and disinhibited in childhood have elevated risk of alcoholism and other substance abuse disorders in adulthood – Caspi et al 1996

– Clinical depression hypothesized to be due to high levels of neuroticism coupled with low levels of extraversion – Watson et al 1994

The nature of personality

Twin Studies on Personality

• Additive genetic factors account for 40-60% of the variance in personality

• Shared environmental influences are negligible• Non-shared environmental effects account for

50% of the variance-different experiences in the same environment-differential parental treatment of siblings or favoritism

-different experiences in different environments --having different friends in school

-reacting to the same event in different ways-parental divorce

• Consistently find little/no personality similarity among adoptive relatives

• Loehlin (1992) – compute weighted-average correlation between nonbiologically related siblings reared together

– Extraversion (3 studies, n=258) -0.07

– Neuroticism (3 studies, n=258) 0.11

– Agreeableness (2 studies, n=250) 0.06

– Conscientiousness (2 studies, n=245) 0.02

– Openness (2 studies, n=241) 0.06

Adoption Studies on Personality

Genes involved with personality

1. DRD42. Serotonin transporter gene, 5HTT3. Monoamine Oxidase 4. Nitric oxide synthase5. Fos B

Cell. 1996 Jul 26;86(2):297-309.  

A defect in nurturing in micelacking the immediate early gene fosB.

Brown JR, Ye H, Bronson RT, Dikkes P, Greenberg ME.

The Fos family of transcription factors

are induced by environmental stimuli that trigger adaptive neuronal

response.

fosB mutant mice are profoundly deficient in their ability to nurture

young animals but are normal with respect to other cognitive and

sensory functions.

The nurturing defect is likely due to the absence of FosB in the

preoptic area, a region of the hypothalamus critical for nurturing.

These observations suggest that a transcription factor controls a

complex behavior by regulating a specific neuronal circuit

- indicates nurturing in mammals has a genetic component.

Association of dopamine D4 receptor (DRD4) with novelty seeking

– Neurotransmitter dopamine has been implicated in brain reward and approach systems

– Novely seeking does not align precisely with any one of the big 5 personality factors but is associated with high levels of extraversion and low levels of conscientiousness

• Impulsive, exploratory and

extravagant

Elovainio, et al. 2005. The mediating role of novelty seeking in the association between the type 4-dopamine receptor gene polymorphism and cigarette-smoking behavior.

Examined the relationship between variation at type 4 dopamine receptor gene and cigarette-smoking behavior and the mediating role of the temperamental novelty seeking.

The two- and five-repeat alleles were significantly more common in the group of current smokers than others (ratio 2.53). After controlling for the effect of novelty seeking on smoking behavior, the relationship dropped substantially, being no longer statistically significant.

Neuroticism and the serotonin transporter gene

http://www.driesen.com/ssrireuptake.jpg

Serotonin is 5-HT (5-hydroxytryptamine), serotonin transporter is 5-HTT

5-HT is serotonin

5-HTT--serontonin transporter (presynaptic side)

5-HTT is also the target of cocaine and methylphenidate5-HT receptors are stimulated by LSD

Association of the serotonin transporter with disease

Polymorphisms in 5-HTT in the promoter region16-repeat- l long14-repeat-s short

‘s’ is associated with reduced transcription and is dominant to ‘l’

Individuals with at least one copy of ‘s’ scored higher on Neuroticism

Association with 5-HTT has been reported for violent suicide and early onset alcoholism

Dopamine plays a role in novelty-seeking behaviorSerotonin is important for neuroticism

Null mutants for the serotonin 1a receptor (5-HT1A) show elevated levels of anxiety

Null mutants for 5-HT1B show reductions in anxietyand elevations in aggression

mutation in a single Dutch family correlates with violent behavior

Null mutants for DRD4 show reduced response to novelty

Studies in knock-out mice

The interaction between low serotonin and high testosterone levels in the central nervous system has a significant effect on the neural mechanisms involved in the expression of aggressive behavior.

Testosterone modulates serotonergic receptor activity in a way that directly affects aggression, fear and anxiety.

• A chronic, severe and disabling brain disease

• Characterized by profound disturbances of cognition, emotion, and social functioning

• 1% of the population develops Schizophrenia during their lifetime

• Affects men and women equally – men in late teens and early 20s; women in 20s and 30s

• Central features include both “positive” (additional behaviors) and “negative” (loss of normal behaviors) symptoms

Schizophrenia

Some people have only one psychotic episode during their lifetime

Others have many episodes during a lifetime but lead relatively normal lives during the interim

Individuals with chronic or recurring schizophrenia often do not fully recover

There is no definitive marker: diagnosis is made

on self-reporting

Schizophrenia

– hallucinations

– delusions

– disorganization of thoughts

– bizarre behavior

– incongruity of affect (improper behavior relative to the specific situation

Schizophrenia - symptoms

Schizophrenia - symptoms

Males have an earlier age of onset than females

male incidence peaks in mid-20s

female incidence peaks around 30

second, lower incident peak around menopause

Schizophrenia – evidence for a genetic influence

• runs in families

• 40-50% risk for monozygotic twins

• 10% risk to child of

affected parent

Schizophrenia – evidence for a genetic influence

Evidence suggests that the predisposition is inherited, not the certainty of developing Schizophrenia itself.

• Based on family studies, current models support existence of two or three susceptibility loci

• liability alleles confer ~ two-fold increase in risk to the sibling of an affected individual

• Linkage studies support this model – identification of several weakly-linked regions of the genome

Genetic models for Schizophrenia

• Schizophrenics are more likely to be born in winter or early spring

Why?some seasonally varying factor alters the developing CNS, increasing an individual’s lifetime risk

parents of schizophrenic patients have an unusual pattern of conception

Environmental Factors

One of the most consistent findings in schizophrenia is that the distribution of birth dates of individuals with schizophrenia differs from that of the general population.

http://www.sciencedaily.com/releases/2003/01/030123072840.htm

“anxiety and aggression” gene?

Are there genes for behaviors?

http://www.sciencedaily.com/releases/2004/05/040526063645.htm

Gene Linked To Alcoholism Alcoholism tends to run in families, suggesting that addiction, at least in part, has an underlying genetic cause. Now, researchers at the University of Illinois at Chicago have discovered a gene linked to alcohol dependency. Laboratory mice deficient in the gene were found to consume excessive amounts of alcohol, preferring ethanol to water and evincing highly anxious behavior in a maze test.

Drunken Fruit Flies Reveal Molecular Pathway Regulating Sensitivity To Alcohol (June 17, 1998) -- Researchers at UC San Francisco have identified a molecular pathway in intoxicated fruit flies that is responsible for regulating the flies' meandering, wobbling

responses to alcohol.

“alocholism” gene?

Variation in a gene calledVariation in a gene calledVMAT-vesicular monoamineVMAT-vesicular monoaminetransporter 2transporter 2

C-correlates with self-C-correlates with self-transcendence, which transcendence, which correlates with spiritualitycorrelates with spirituality

A-does notA-does not

Reported in a book by Reported in a book by Dr. Dean Hamer, Dr. Dean Hamer, The God The God Gene: How faith is hardwired Gene: How faith is hardwired Into our genesInto our genesChief of gene structure, NCIChief of gene structure, NCI