The Biological Approach EVOLUTION GENETICS BIOLOGICAL STRUCTURES Starter

The Biological Approach EVOLUTION, GENETICS & BIOLOGICAL STRUCTURES

Starter Questions Answer in pairs on mini-whiteboards: 1. What three aspects of biology do we look at under the biological approach? 2. What does the term ‘natural selection’ refer to? 3. What does the term ‘adaptive’ mean in the context of evolutionary theory 4. Give an example of an evolutionary theory that we have looked at in one of the topics 5. What do the terms ‘genotype’ and ‘phenotype’ refer to? 6. To test for a genetic link in behaviour, psychologists often use twin studies. What is always the IV in these studies? 7. What does the term ‘concordance rate’ refer to in the context of twin studies? 8. Twin studies rarely show 100% concordance rate. What does this suggest? 9. What are the two parts of the nervous system? 10. What are neurotransmitters? 11. Name the four lobes of the human brain 12. What does the term ‘neural plasticity refer to? 13. What does the endocrine system do?

Starter Questions: Answers 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. What three aspects of biology do we look at under the biological approach? 1. 2. Evolution, genetics, biological structure (nervous system, endocrine system) The belief that those who have the characteristics best suited to the environment What does the term ‘natural selection’ refer to? will survive long enough to pass their genes on to the next generation What does the term ‘adaptive’ mean in the context of 3. The genes that promote survival and successful reproduction will be the ones that evolutionary theory get passed on, and so the species adapts accordingly (not the individual) Give an example of an evolutionary theory that we have e of attachment. Seligman’s genetic preparedness theory 4. Bowlby’s theory looked at in one of the topics nd th a m e t s ise the genetic make up of the individual that has been inherited from the us sy 5. Genotype o v v a r h What do the terms ‘genotype’ and ‘phenotype’ refer to? e n u o y The phenotype is the observable characteristics, which will depend on temparents. s y s e n i e r To test for a genetic link in behaviour, psychologists often h c t o in & environment d genes en use twin studies. What is always the IV in these studies? in detail d is are MZ or DZ e 6. Whether they Th ver. c co i p o t What does the term ‘concordance rate’ refer to in the holog 7. y Theatpercentage c context of twin studies? y on the of time if one twin displays the behaviour, the other will too s p e o i r B t n cannot be wholly down to genetics on 8. ce Behaviour c d l l i n Twin studies rarely show 100% concordance rate. What a w h n c roa & peripheral 9. app Central does this suggest? lesso y r a n ll eramessengers Chemical that influence mood and behaviour v o evolutio a 10. n What are the two parts of the nervous system? a d n s h Frontal, oac occipital, temporal prparietal, genetic 11. p a What are neurotransmitters? e h t f The fact that the brain can change and adapt as a result of experience ation o 12. Name the four lobes of the human brain evalu 13. It is responsible for secreting hormones into the bloodstream 12. What does the term ‘neural plasticity refer to? 13. What does the endocrine system do?

The biological Approach: Exam Practice Answer the question individually, without notes Rita and Holly are identical twins who were separated at birth. When they finally met each other at the age of 35, they were surprised at how different their personalities were. Rita is much more social and out-going than Holly. Use your knowledge of genotypes and phenotypes to explain this difference in their personalities (4 marks) Now use the guidance on the next slide to award a mark to your answer

The biological Approach: Exam Practice Mark Scheme Award one mark for each of the following: Holly and Rita have identical genotype as they are MZ twins. They have the predisposition to develop the same personalities as each other unless another factor(s) intervenes. For them to have developed different personalities over time, this must have been influenced by being in different environments. Their phenotypes – personalities achieved – are different, presumably because Rita was encouraged to be sociable and lively and Holly was not.

Evolutionary theory: Application exercise In your groups, on MWBs, explain the following behaviours in terms of evolutionary theory. Remember there is no cognitive element, so thought processes should not play a part in your answers Older men being attracted to younger women

Evolutionary theory: Application exercise In your groups, on MWBs, explain the following behaviours in terms of evolutionary theory. Remember there is no cognitive element, so thought processes should not play a part in your answers Being able to recognise other people’s emotions

Evolutionary theory: Application exercise In your groups, on MWBs, explain the following behaviours in terms of evolutionary theory. Remember there is no cognitive element, so thought processes should not play a part in your answers Women having greater levels of empathy than men

Evolutionary theory: Application exercise In your groups, on MWBs, explain the following behaviours in terms of evolutionary theory. Remember there is no cognitive element, so thought processes should not play a part in your answers Fear of spiders

Genetics: The case of the Jim Twins • • After watching the clip, you will be asked to evaluate the research • Split your group into two One half, on MWBs come up with reasons why Bouchard’s research with twins is good evidence for the genetic basis of behaviour The other half come up with problems with using this research to support a genetic basis of behaviour Now take turns to present your argument to the other half of your group You will be asked to summarise all of the points following your discussion and to say which side had the strongest argument

Genetics: An analysis of Bouchard’s twin research Findings from Bouchard’s Reseach into concordance rates for Intelligence % Identical twins reared together 86% Identical twins reared apart 72% Non-identical twins reared together 60% Biological siblings reared together 47% Parent and child living together 42% Cousins 15% Unrelated people living apart 0% Same person tested twice 86% In pairs on MWBs: Look at the results in the table on the left Select a pair of findings that suggest something about the biological basis of intelligence Write a statement explaining what that pair of results suggest Now repeat that process for two more pairs of findings

Genetics: An analysis of Bouchard’s twin research Did you get: Identical twins reared apart have a much higher concordance rate (72%) than ordinary siblings reared together (47%) suggesting that genetics have a much greater influence on intelligence than environment There is not a great deal of difference between the concordance rates of identical twins reared together (86%) and identical twins reared apart (72%), suggesting that environment has a limited effect on intelligence Identical twins reared together have a much higher concordance rate (86%) than non-identical twins reared together (60%), suggesting that, as they are both raised in the same environment at the same time, genetics must account for the greater similarity between the MZs, but as the concordance rate is not 100%, environment must play a part The same person tested twice has the same concordance rate as identical twins reared together (86%). This raises the issue of whether the measure of intelligence lacks reliability, and if so, does this mean that potentially their could potentially be perfect concordance between the identical twins raised together?

The Biological Approach: Evaluation Answer the questions in your groups on MWB The biological approach uses the experimental method, thus increasing the scientific validity of the approach. Recent advances in brain imaging techniques have further increased the objectivity and scientific validity of the research. However, it is still not possible to precisely study the effect of biology on behaviour, as it is not possible to fully separate nature from nurture. Why not? List possible reasons • • • Observed differences in brain structure or neurology between those with a particular condition and those without it, e. g. high levels of dopamine in the brains of those with OCD, may be caused by the condition. This problem arises from the research being retrospective Twin studies, which the biological approach relies on quite heavily, are natural experiments, which means we cannot be sure if there are other, environmental differences between MZ and DZ twins that could account for the differences. Like what? In addition, the concordance rate for MZ twins is rarely 100%, meaning that they do not fully support the biological approach Now, in pairs, see if you can write a PEEL point using this information

The Biological Approach: Evaluation Answer the questions in your groups on MWB Which part of the biological approach does not use scientific methods to support its theories? onary i t u l o v e The h approac Why is this? • The evolutionary approach is based purely on speculation • This is because theory is retrospective. we cannot go back in time and test it • Therefore, we make assumptions about why certain behaviours are prevalent, which may have ‘common sense appeal’, but cannot be tested scientifically

The Biological Approach: Evaluation Answer the questions in your groups on MWB The biological approach is reductionist. What does this mean? It simplifies behaviour down to its basic biological components. E. g. , someone is depressed because they have low serotonin levels Why might reductionism be considered a good thing? (think about what it might lead to) Because it allows us to establish a cause for a behaviour, which is a key part of a scientific approach, as it leads to useful applications. For example, if we know that low serotonin levels cause depression we can develop therapies to increase serotonin levels Why might reductionism be considered a bad thing? (think about what it ignores) Because it ignores other factors (e. g. environmental, cognitive) that may play a part in behaviour, thus preventing us from having a complete understanding of behaviour and consequently does not provide us with an effective long term treatment for the problem. Most research suggests that an interactionist approach is more useful in helping us understand behaviour