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DNA to Society - Coggle Diagram
DNA to Society
Genetics
nature and nurture don't work in isolation
- genes and other biological systems interact with our life experiences and mental processes.
- phenotype: the observed characteristics of an organism
- genotype: the genes that code for the organism's characteristics
- allele: a specific variation of a gene
- a genotype influences the phenotypic traits we observe, but the environment almost always plays a role.
- identical twins with identical genotypes will have some minor phenotypic differences in fingerprints, facial features, and personalities
psychological factors like our personality and inherited risk of mental illnesses are usually polygenic
- the phenotypic trait is influenced by multiple genes.
- the overwhelming majority of mental illnesses have a polygenic risk factor.
- exception: early-onset alzheimer's disease
- 3 known deterministic genes: PS1, PS2 and APP >> if you inherit just one of these genes, you WILL develop alzheimer's before the age of 60
- APO-E > increases the RISK of developing alzheimer's but does not guarantee that you will develop the disorder.
some genes increase the
risk of mental illness by influencing
the way a person responds to
different life situations
gene-environment correlation model
- inheriting certain genes can attract trouble in your life
- studies into bullying showed that genetics was the prime factor in determining whether the child was bullied, a perpetrator of bullying, or either in specific caes.
- traits like low self-esteem can be strongly influenced by a child's genetics >> children with a genetic predisposition to behave in a self-deflating way can elicit hostile treatment from their peers.
epigenetics
- factors outside the genome that affect the expression of genes
- epigenome: stuff outside the DNA that controls which genes are turned on or off.
- the environment a person encounters changes which genes are turned off and which are turned on >> these changes caused by environmental factors can be passed down through generations
diathesis-stress model
- explains that a person will inherit a certain risk factor, like the APO-E gene, and that risk factors leaves the person vulnerable to developing mental illness but ONLY IF they're ever faced with particular life stressors.
- its entirely possible for a person to carry this genetic risk and live their life without ever developing the disorder.
- inheriting certain genes can increase your risk of experiencing negative life events.
Fight, Flight and the
HPA Axis (Neuroscience)
the human nervous system is made up of neurons
- they have a body cell called a soma, dendrites (which allow them to receive messages from other neurons), an axon (conducts an electrical), and a terminal button.
- the place where two neurons meet is called a synapse > neurons don't actually touch each other.
- microscopic gap called the synaptic cleft.
- neurons "firing": an electrical signal being sent down an entire neuron to a neighbouring neuron.
- technical term is called an action potential
- when a neuron has fired its action potential, this electrical signal triggers the release of neurotransmitters from the terminal button into the synaptic cleft.
- these neurotransmitters fit into receptors on the receiving neuron like a key in a lock.
- some neurotransmitters are excitatory and increase the receiving neurons potential to fire, whilst others (inhibitory) decrease the receivers potential to fire,
- after, neurotransmitters disconnect from the receptor and go back up into the terminal button >> reuptake.
- SSRIs >> selective serotonin reuptake inhibitors (sometimes prescribed to people with depression) >> prevent the reuptake of serotonin so it can have a longer-lasting effect
mamalian nervous system
- CNS >> central nervous system: brain, spinal cord
- PNS >> peripheral nervous system: everything else.
- somatic nervous system: controls voluntary skeletal muscles
- autonomic nervous system: controls automatic behaviours
- controls endocrine system: a collection of glands scattered throughout the body that communicate with each other through chemicals called hormones
- sympathetic nervous system: controls fight or flight, prepares body in stressful events
- parasympathetic nervous system: calms body down again
hpa axis
- hormones are released into the bloodstream and bind to receptors that control a large range of functions like metabolism, growth, hunger, etc.
- pituitary gland: sits at the base of the brain underneath the hypothalamus. when you experience a stressful event, the hypothalamus releases hormones that tell the pituitary gland to release hormones.
- adrenal glands hormones from the pituitary gland tell the adrenal glands to release hormones like cortisol, that rapidly break down fat into sugar, quickly giving energy in stressful events.
- cortisol also shuts off the stress response after a stressful event >> when the brain's cortisol receptors detect a lot of cortisol in the blood, it shuts off the stress response so we can calm down again >> the more cortisol receptors in the brain, the faster the shut-off
Emotion, Learning
and Cognition
- william james: when we experience an emotional situation, our body reacts first and our brain labels that suite of physiological symptoms afterwards.
- strong link between the facial expressions we make and the moods we feel as a result.
- 6 basic emotions seem to be universal: joy, sadness, fear, disgust, anger, surprise
- each of these emotions seem to serve an evolutionary function. given that humans are social animals, having the ability to communicate our feelings to each other would have improved our ability to survive and pass on genes to offspring.
- the sociality of our emotions seems to be ingrained in our physiology
- the sadder people are, the more their pupils dilate.
- other people's emotions also have the ability to affect our own physiology >> the more dilate the pupils of the person you're looking at, the more your own pupils dilate.
- our entire emotional response to a situation: the thoughts we think, our physiological response, and our emotional reactions) seem to be governed by schemas
- schemas: our conceptual understanding of a stimulus
- schemas contain and organise all our knowledge about a particular person, object, topic, or scenario.
- self-schema: how to view yourself, your strengths, weaknesses, beliefs, values, etc.
- all of your schemas influence how you appraise encounters with different stimuli and different situations.
- schemas influence how we see the world.
- attentional bias> + appraisals can explain why two people experiencing the same situation can react so differently
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