Sex, Gender, and Personality

Physiology of Personality Overview

• The study of the physiology of personality examines impulsivity, anxiety, and introversion/extraversion.
• The goals are to understand skin conductance, arousal, and the functioning of BIS/BAS.

Connection of Mind to Body

• Elliot was a successful businessman with strong social skills who developed severe headaches leading to the discovery and removal of a brain tumor affecting a small part of his prefrontal cortex.
• Post-surgery, Elliot's cognitive functions, including IQ and memory, remained intact.
• Elliot's personality changed, hindering time management and task completion, leading to job loss and financial downfalls, and he reported feeling little to no emotion.
• Elliot's case shows how organ systems, especially the nervous system, play a role in personality.
• Further studies support that brain injury can affect personality.
• Physiological systems include the nervous system, cardiac system, and musculoskeletal system.

Importance of Physiology

• Physiological differences can create, contribute to, or indicate differences in personality.
• People vary sensitivity to their nervous systems to stimulation distractions.

Physiological Approach

• A physiological approach focuses on which traits connect to psychological reactions under specific conditions and stimuli.
• Physiology contributes to behavior but does not control it.

Measuring Neuroticism by Skin Conductance

• Higher neuroticism correlates with higher skin conductance.
• Salt ions in sweat conduct electricity, and the better it conducts due to sweat, shows high neuroticism.
• High neuroticism is shown even in the absence of stimuli,.

Arousability and Introversion/Extraversion

• Arousability is related to introversion and extraversion, which is connected to the ascending reticular activating system (ARAS).
• Donald Hebb theorized that everyone aims for an "optimal level of arousal," a state of being focused without boredom or anxiety.
• Introverts and extraverts achieve optimal arousal differently.
• Introverts have a stronger arousal response and the ARAS lets in more stimulation, so they don't need much arousal from the environment, and extraverts have weaker arousal responses and the ARAS lets in less stimulation.
• Extraverts seek out arousal in their environment.

Geen, 1984 Study

• Participants high in extraversion or introversion were chosen for a learning task with background noise.
• Group 1 choose their noise volume; Introverts chose a quieter level (55 decibels) than extraverts (72 decibels).
• Group 2 was given the same noise levels chosen by their peers; Introverts got introvert volume, extraverts got extravert volume.
• Group 3 was given the opposite noise levels as their peers; Introverts got extravert level and extraverts got introvert level.
• Extraverts performed best when listening to extravert-level noise, with their blood pressure increasing, but introverts’ blood pressure increased even more.
• The blood pressure effects were reversed at lower noise levels but not performance.
• Introverts performed best at the lower noise level.
• Introverts find a certain level of arousal “just right,” while extraverts may find it boring, and vice versa, which also affects performance.

Behavioral Activation and Inhibition of Impulsivity and Anxiety

• Behavioral Activation System (BAS) sensitivity is determined by the sum of scores from the earlier survey question numbers 1, 3, and 6.
• Behavioral Inhibition System (BIS) sensitivity is determined by the sum of scores from the survey question numbers 2, 4, and 5.
• Higher sensitivities show the level of BAS/BIS.

Reinforcement Sensitivity Theory

• Reinforcement sensitivity theory involves reward and punishment.
• The function is based on two systems in the brain: Behavioral Inhibition System (BIS), and Behavioral Activation System (BAS).
• Behavioral inhibition system (BIS) regulates strength of response to punishment, frustration, uncertainty, leading to avoidance behavior and compared to stop sign.
• A stronger BIS than BAS is associated with anxiety.
• Behavioral activation system (BAS) regulates strength of response to incentives & reward, leading to approach behavior and compared to accelerator.
• A Stronger BAS than BIS is associated with impulsivity.

Research on BAS/BIS

• Measures participants' BAS/BIS and participants do a reaction time task such have to say what the color of a word is quickly.
• Two groups: one group that is subjected to punishment starts off with $10 and loses money every time they get one wrong, and subject to reward starts starting off with nothing earning money every time you get one right
• Stronger BAS perform better in the reward group
• Stronger BIS perform better in the punishment group
• Two types of learning(reinforcement and punishment) may be controlled by separate brain systems
• Stronger BAS leads to impulsivity, so people learn well from reward
• Stronger BIS leads to anxiety, so people learn well from punishment
• Anxiety patients score are higher on BIS and Criminals score higher on BAS.
• If someone is BAS, reward their behavior and BIS, punish their behavior.

MAO and Sensation-Seeking

• Identify the implications of too much/too little MAO.
• Understand how Clonginger's tri-dimensional model explains differences in .
• Explain how all of these theories fit together
• High in sensation-seeking has a tendency to seek out thrilling and exciting activities, take risks, and avoid boredom.
• Being high is linked to risker bets in gambling, more sexual partners, and Skydiving.
• Neurotransmitters are chemicals that are released from nerve cells (chemical messengers) that carry messages from one nerve to another where they must be removed from the synapse after the message has passed.
• Neurotransmitters are broken down by enzymes (one is MAO).
• If there is too much MAO, the neurotransmitter is broken down too quickly, resulting in too few messages getting through.
• If you have too little MAO, the neurotransmitter is broken down too slowly resulting in too many messages getting through
• Women have higher digit ratio and linked to lower sensation seeking, risk-taking and dominance.
• Lower ratio is linked to sensation seeking, in riskier lotteries, more traffic violations and careers in finance.
• Low sensation seeking leads to too much MAO.
• High sensation-seeking leads to too little MAO, with neurotransmitters being broken down slowly and having less control over thoughts and behaviors.
• Impulsivity is linked to low levels of MAO.

Clonginger's Tri-dimensional Model

• The model involves dopamine (novelty seeking), serotonin (harm avoidance), and norepinephrine (reward dependence).
• Dopamine is a neurotransmitter associated with pleasure, is the "feel-good chemical", and animals work to obtain it, with drugs of abuse mimicking it and leading to increased pleasure, then the unpleasant feels after, lead you to want to get it again.
• Low dopamine creates an urge to obtain substances/experience(thrills, novelty and excitement) that increase dopamine.
• One type of dopamine(DRD4) gene has been linked to seeking novelty and serotonin is linked to depression, anxiety, and impulse control.
• Lower levels of serotonin is to linked to harm avoidance (always on the lookout for something that will harm you).
• In monkeys with low levels of serotonin are fearful and that have low level of serotonin have severe anxiety.
• Influences learning (through reward systems) so lower level of Ne might mean reward-dependant.
• A person work harder for reward being responsive, empathetic, dependent.
• High Ne is independent and socially detached
• May be linked to novelty seeking and harm avoidance

Morningness-Eveningness

• Morningness-eveningness is when you have a "show of hands", who's more of the early bird and who's more of the night owl.
• Morningness-eveningness appears to be a stable characteristic due to biological rhythms of 24-25 hours with body temps varying and endocrine secretion rates.
• Temporal isolation design (no windows, not scheduled meals whenever told and tons of streaming),sleep whenever they want whenever and allows "free running" of time. and also research peoples "natural circadian rhythm".
• The wide difference is revealed once the controlled studies showed how it affected people as it only fit with 24hr day of nature and light.
• A person with 22hr clock means sleepy earlier in the day or 26hr meant sleepy later in the day while the regular time.
• Shorter clock = morning person and longer meant evening person and if you were longer than the instructor would be sleepy.
• It may be able to tell through the personality of a person.
• How someone said early to be and you know thing is more for person healthy wealthy like grades and study design.
• If morning and evening fit together show a predictive compatibility like relationship that can be successful as it is used as roomates/relationships.