hormones and pheromones behaviour Flashcards
what is the endocrine system?
it consists of glands that release chemicals/hormones into the bloodstream. these hormones then affect receptors on or inside cells, including neurons. the immediate effect is therefore physiological effects (most also have psychological and behavioural effects)
endocrine system is in many ways similar to the nervous system. the function is to coordinate physiological activity, and to prepare the body for action.
difference between neurotransmitters and hormones
neurotransmitters are released into the synaptic gap while hormones are released into the bloodstream.
the direct effects of neurotransmitters are short term, while hormones released into the blood stream will be available there for some time. hormones are chemical synthesized in endocrine glands, while neurotransmitters are chemicals synthesized in neurons.
hormones bind to receptors located at the cell membranes or inside the cell, while neurotransmitters bind to receptors located at the postsynaptic membrane. hormones can affect the structure of the body, while other can affect the structure of the receiving neuron
similarities of neurotransmitters and hormones
both can have behavioral effects. drugs can mimic both and produce the same or similar effects. in both cases, cells produce and release chemicals. both have physiological and psychological effects.
how many times do men produce more testosterone than women?
10 times more
what do the behavioral effects of testosterone include?
increased well-being, competitiveness, dominance, aggression, and sexual behavior.
where is melatonin produced?
in the pineal gland
testosterone (glands, variations in production, physiological effects, behavioral effects)
glands:
testes in men and ovaries in women; adrenal gland
variations in production:
1) an average man produces 10 times more than an average woman. individual variation is huge; females are more sensitive to T.
2) production of T varies over the life-span
3) production and release of T varies over the day
4) production and release of T varies with behavior.
physiological effects:
muscle mass, bone structure and hair growth
behavioral effects: sex drive, well-being, dominance, status, aggression, competition, risk-taking, decision making.
study 1 (hormones and behavior)
J.M. Dabbs et al (1995) testosterone, crime, and misbehavioral among 692 male prison inmates.
aim: to study the relationship between testosterone and kind of offence and misbehavior in prison.
pps: 692 male prison inmates from a security state prison. two-thirds were Afro-Americans and one third eas Caucasians. mean age was 19.8.
procedure: saliva samples to analyze amount of testosterone. based on T levels, one third were categorised as having a low T level, one third as having a mid T level, and one third a high T level. for each pps the crime they were serving time for at present was recorded. violent crimes: robbery and assault. non-violent: burglary and drug offenses.
results: there was a relationship both between testosterone level and kind of crime and between testosterone level and misbehavior in prison. pps with high T levels were more likely to serve time for a violent crime (10 out of 11 inmates) and to have violated prison rules. and those pps who had T at mid-levels were more likely to serve time for a violent crime and to have misbehaved than were those who had lower levels of T. 9 out of 11 with the lowest levels had committed a non-violent crime.
study 2 (hormones and behavior)
Ronay et al (2010) the presence of an attractive woman elevates T and physical risk-taking in young men.
aim: to investigate the hypothesis that physical risk-taking by young men increases in the presence of an attractive female; and that increased risk_taking in the presence of an attractive woman might be included by elevated T.
pps: 96 young adult male skateboarders( age M_21.58).
procedure: 43 pps were assigned to male-experimenter condition and 53 to female-experimenter condition. testing eas conducted between 1pm and 6pm to control for variation in T concentrations. pps were asked to choose one easy trick and one difficult trick, each of which they then attempted 10 times while being video-recorded by a male experimenter or an attractive 18-old female experimenter who was blind to hypotheses. attractiveness of the female experimenter was established by 20 independent male raters. saluve samples.
results: pps took great risks on the difficult tricks in the presence of the female experimenter, leading to both crash landings and successful tricks. T levels were significantly higher among men who skateboarded in front of the female experimenter. the analysis suggests that increased risk-taking in front of the female experimenter was partially mediated by increased testosterone levels
study 3 (pheromones)
Zhou et al (2014) chemosensory communication of gender through two human steroids in a sexually dimorphic manner.
background: androstadienone(AND)- found in male semen and sweat. estratetraenol (EST)- found in female urine.
aim: to test the qualification of the two steroids as sex pheromones AND and EST by examining whether they communicate gender information in a sex-specific manner, thus investigating if these substances influence human sexual behavior.
pps: 96 pps: 24 heterosexsual men, 24 heterosexual women(included sels-reported bisexual females), 24 gay men and 24 lesbian women.
procedure: pps were asked to watch stick figures walking on a screen and to determine their gender. while carrying out the task, pps were exposed to the smell of cloves in identical small jars from which pps inhaled during the experiment. in the first condition, cloves were mixed with AND and in the second condition the cloves were mixed with EST and in control condition only cloves were used.
results: smelling AND biased heteresexual females and gay males towards perceiving the walkers as more masculine. by contrast, smelling EST systematically biases heterosexual males and lesbian women toward perceiving the walkers as more feminine. the results from bisexual and homosexual females fell in between those of heterosexual males and females
conclusion: pheromones influence communication of gender information in a sex-specific manned.
study 4 (pheromones)
Hare et al (2017) putative sex-specific human pheromones do not affect gender perception, attractiveness ratings or unfaithfulness judgements of opposite-sex faces.
aim: to investigate the effects of the putative (“thought to be” or “supposed”) sex pheromones AND and EST on perceptions of facial gender, attractiveness and unfaithfulness.
pps: self-reported heterosexual, non-smoking, adult Caucasian pps (43 male and 51 female; mean age=23.7) from the Uni of Western Australia campus.
procedure: pps completed two computer-based tasks twice, on two consecutive days, exposed to a control scent(smell) on one day and a putative pheromone (AND or EST) on the other. the first task tested perceptions of gender, and the second task assessed perceptions of attractiveness and unfaithfulness. in the first task(2-5 min), 46 pps(24 male 22 female) indicated the gender of five genderneutral facial morphs. in the second task(10-25min), 94 pps (43 male 51 female) rated photographs of opposite-sex faces, each on a scale from 1(low) to 10.
results: exposure to AND or EST had no effect on gender perception. exposure to the putative pheromones had no effect on either attractiveness or unfaithfulness ratings.
