Biological (physiological) Approach: Seeks to explain mental process & behaviour by focusing on the function of the nervous system at the cellular and structural level.
Theorists in the bio study behavioural genomics consider how genes affect behaviour. Factors such as chromosomes, hormones & the brain all have sig influence on Human behaviour. E.g Gender.
Hormones like oestrogen make females more emotional. Testosterone make Males more aggressive & violent.
Bio believes most behaviour is inherited & has an adaptive (evolutionary) function. E.g In weeks immediately after birth of a child, testosterone lvls drop in Farther by more than 30%. Evolutionary function as they are less likely to wander off & find new mates & less aggressive when the baby is around.
Bio explains behaviour in neurological terms e.g physiology & structure of brain & how it influences behaviour. Many psychologists concentrate on abnormal behaviour and tried to explain it. E.g believe SZ affected by lvls of dopamine.
Neurotransmitter are brain chemicals that communicate information throughout the brain. They relay signals between neurons.
Key beliefs:
Role of CNS in behaviour: Nervous system including the brain is made up neurones that convey messages around the body. Within a neurone an electro-chemical message called a nerve impulse. There are minute gaps between neurons which chemical messages pass across called neurotransmitters. By passing messages on from neuron to neuron, neurotransmitters are responsible for behaviour. Crucial for functions of the brain & messages sent to the rest of the body.
Neurotransmitters are brain functioning only sent between synaptic cleft, Hormones are Long term messengers released into blood stream
Brain functioning & behaviour (aggression): The brain is made up on billions of interconnected neurons, receiving input through sensory neurones from each of the senses of info such as pain & sends output to rest of the body.
The brain is organised into specialised areas; PFC responsible for personality expression & planning of complex cog behaviours, emotional responses & control of social inhabitation – damage would lead to problems with personality & unable to break out aggression.
E.g Phineas Gage had an iron rod driven through his PFC which have behavioural issues making him more impulsive.
Evolution & natural selection in human behaviour: To understand human behaviour we must look at our evolutionary past & reasons for displaying behaviours, such as reproductive fitness. A major concern for male ancestors was to find a mate & when having one maintaining influence over her. In a way this was aggressive behaviour adaptive to prevent her from leaving & explains male sexual jealousy today.
Explains why men & women should seek different qualities in a partner; men want a young women of reproductive fitness whilst women value a man with resources (money, food, shelter). As men want a woman who is fertile & women seek a man who will look after her child.
| Strengths | Weaknesses |
| Provides clear predictions about the effect of neurotransmitters or behaviour of ppl who are genetically related – explanation scientifically tested & proven
Uses scientific research methods such as PET & MRI scans. Images produced can be objectively interpreted by more than one researcher reducing bias. Involves animals in lab experimentation where It would be unethical to use human patients. Such experimentation involves high lvl of control over EV as environment can be controlled during & prior to research.
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Such experimentation involves taking ppts out of their natural environment in order to study human/animal behaviour. Lacks ecological V as behaviour not reflect real world use
Cannot establish causal relationship with bio. A neurotransmitter linked to aggression is Serotonin; low lvls cause of aggression however could be aggression that causes low lvls. Too deterministic – belief that all events cause by things that happened before them & ppl have no ability to make choices or control what happens. May have limited application as little can be done to prevent it. Consider intervention such as eugenics higher reproduction of desired traits & sterilisation of ppl with less desired or undesirable traits. THIS IS UNETHICAL Reductionist – ignores the role of nurture on behaviour & disregards important environmental influences & fail to provide enough info to fully explain human behaviour. May be predisposed to certain behaviour but may not exert themselves unless triggered by environmental factors. |
The Brain:
Cerebral Cortex (Humans only)
Temporal lobe: handles most of our memory functions. Damage can lead to memory problems.
Frontal Lobe: handles conscious planning (PFC) important for self-control & decision making & handling aggression.
Occipital Lobe: at the back of your brain, processes sight & senses of our environment.
Parietal lobes: controls language & specialises in touch & directing body movements.
Limbic systems: (we share these with animals) (basic part of the brain)
Most important area is the thalamus sitting at centre. ‘Switch board’ as it handles messages coming to & from the brain.
Limbic system handles memories, raw appetite, desires (sleep, hunger, aggression, sex) source of basic emotions.
Areas: Thalamus (hypothalamus), amygdala, hippocampus.