Discuss ethical considerations in research into genetic influences on behaviour

Genetic research can pose risk to participants because of the link between genetic heritage and people's life. Genetic information can be stigmatising and may affect people's ability to get jobs or insurance.

During study

• Participant should know their privacy and confidentiality will be protected.
• What will happen to genetic information obtained as a result of the study should be disclosed.
• Aim and procedure of the study must be explained understandably.
• Informed consent form must be signed.

Confidentiality and Privacy

• Can be protected by providing codes for identification of each participant (anonymising).
• Protects confidentiality from insurance companies, employers, police and others, but also limits scientific value by limiting follow up and further investigation.

Genetic research itself - things to consider

• Can reveal unexpected information that ay harm participants e.g. evidence of misattributed paternity or unrevealed adoptions in a family (awks).
• Also discovery of carrying a gene for a genetic disorder, which can cause stress and problems with insurance.
• Some groups may have objections to genetic study as a cultural principle, given history of discrimination and especially the eugenics movements.

With reference to relevant research studies, to what extent does genetic inheritance influence behaviour?

Behaviour - intelligence.

Two factors affect intelligence - genetics and environment (nature vs nurture). To what extent does genetics influence intelligence? This can be investigated through the use of twin and adoption studies, as you are able to observe and compare genetics and environment in both situations.

Twin Studies - investigating genetics (compare intelligence of twins, correlation can be attributed to genetics, as they share genetic material).

Bouchard and McGue (1981)

• Conducted a meta-analysis of 111 studies of siblings.
• Investigated IQ correlations between siblings.
• Found that there was a positive correlation between kinship and IQ correlation - the closer the siblings were, the more similar their IQ.
• Evaluation of study: 
• Large study, so generalisable.
• However, siblings are raised in the same environment, so influence may not be purely genetic, and it is difficult to differentiate between influence of genetics and environment.
• Also, age - the further apart the siblings in age, the less correlated their IQs are expected to be.

In order to investigate the role of genetics by itself, identical twins that are raised separately from birth must be studied. Identical twins have a 100% genetic relationship, but if raised in separate environments, any similarity (beyond that expected by chance) in IQ must be due to similarity in genetics.

Bouchard et al. (1990) - Minnesota Twin Study

• Conducted a longitudinal study since 1979, comparing MZA twins to MZT twins in terms of intelligence (MZA - monozygotic raised apart, MZT - monozygotic raised together)
• Each twin completed approximately 50 hours of testing and interviews.
• It was a cross cultural study, using participants from all over the world.
• Results - concordance rates of intelligence from the study

Same person	87%
MZA	86%
MZT	76%
DZT	55%
Siblings reared together	47%

Bouchard et al. determined a heritability estimate of 70% - 70% of intelligence can be attributed to genetic inheritance. 30% attributed to other factors.
Evaluation of study:

Strengths	Weaknesses
- Size of the study means it is more generalisable - Nature of sample - cross cultural - Mean age of participants 41 years, as opposed to previous studies with adolescents	- Relied on media coverage to recruit participants - Ethical concerns with the way twins were reunited - Frequency of contact between twins prior to study not controlled. - 'Equal environment assumption' - twins reared together may not have experienced the same environment.

Adoption Studies - investigating environment (no biological/genetic link between parents and child, so correlation in IQ is purely due to environment)
Horn et al. (1979)

• Conducted a study on parents who raised BOTH adopted and natural children.
• All children have the same upbringing, therefore same environment, but some were similar in genetics and some were not.
• Found no significant differences in correlation of parent-child IQs between natural and adopted children.
• Adoptive parents were wealthy, white, middle class and children were poor, lower class backgrounds, with lower IQ parents.
• Conclusion that genetics has little impact - mostly environment.

Wahlstein (1997)

• Well controlled adoption studies in France
• Transferred infant from family with low socio-economic status to with high economic status parents.
• Increased IQ of children by 12-16 points.
• Suggests that environment has a lot to do with intelligence, as well genetics - enriched environment = good.

Both genetics and environment influence intelligence equally?

Command Term Glossary

Level 1:

Define
Give the precise meaning of a word, phrase, concept or quantity.

Describe
Give a detailed account.

Outline
Give a brief account or summary.

State
Give a specific name, value or other answer without explanation.


Level 2:

Analyse
Break down in order to bring out the essential elements or structure.

Apply
Use and idea or theory in relation to a given problem or issue.

Distinguish
Make clear differences between two concepts or items.

Explain
Give a detailed account including reasons or causes.


Level 3:

Compare
Give a detailed account of similarities between items, referring to all of them throughout.

Contrast
Give a detailed account of differences between items, referring to all of them throughout.

Discuss
Offer a considered and balanced review that includes a range of arguments, factors or hypotheses. Opinions or conclusions should be presented clearly and supported by evidence.

Evaluate
Make an appraisal by weighing up the strengths and limitations.

Examine
Consider and argument or concept in a way that uncovers the assumptions an interrelationships of an issue.

To what extent
Consider the merits of otherwise of an argument or concept. Opinions and conclusions should be presented clearly and supported with appropriate evidence and sound argument.

Examine one evolutionary explanation of behaviour.

A principle of evolutionary psychology is that as genes mutate, those that are advantageous are passed down through a process of natural selection. This is derived from Charles Darwin's theory of evolution, which states that all living things are related and descended from a common ancestor. Darwin explained this through his theory of natural selection, which is a mechanism through which all life came to be related - members of a species who have characteristics that are better suited for their environment, or are favourable for their environment, are more likely to survive to a reproductive age and pass on those characteristics to their offspring. Hence, offspring have those characteristics, which are passed down, etc. These characteristics can be physical traits or behaviours, which advantage the individual.

Evolutionary psychologists attempt to explain how certain human behaviours show how humans have developed over time. Certain behaviours can be explained by examining their evolutionary origins and their identifying their ability to enhance survival. For example, the emotion of disgust.

 Fessler (2006)

• Investigated women's experiences of nausea in first trimester of pregnancy (resulting in morning sickness).
• During the first trimester, hormones suppress the immune system in order to accustom the body to the foreign genetic material growing in the womb.
• He hypothesised that the heightened sense of disgust experienced by women during this time was the body's way of compensating for the lacking immune system.
• Participants: 496 healthy pregnant women, ages 18-50.
• Asked them to consider 32 disgusting scenarios, and rank disgustingness.
• Women in their first trimester consistently ranked higher than their counterparts in second and third trimesters in terms of disgust-sensitiveness.
• As many of the most harmful diseases are food-borne, Fessler concluded that a heightened sense of disgust was advantageous to our ancestors and allowed them to survive long enough to produce offspring, who passed on the same sensitivities.
• It would have helped compensate for the increase susceptibility to disease during early pregnancy, which is a risky period due to the suppressed immune system, by increasing the urge to be picky abut food.
• This would diminish the risk of food-borne disease during pregnancy, which is according to the view of disgust as a form of protection against disease.

Curtis et al. (2004)

• Investigated whether there were patterns in people's disgust responses.
• Participants: 77 000 altogether, from 165 different countries.
• Conducted an Internet based survey in which participants were shown series of 20 photographs, an asked to rank each image for how disgusting it was.
• There were seven pairs in which one was infectious and a matching image was not (e.g. body fluids, coloured liquid).
• Those images containing substances that would most strongly harm the immune system were rated highest on disgustingness.
• Disgust decreased with age and female were more disgusted than males, which supports the idea that disgust is a form of protection to enhance chances of successful reproduction.

There are some points to consider when using evolution-based explanations for behaviour:

1. It is difficult to test evolution-based theories empirically, so researchers may be susceptible to confirmation bias (finding results that they expect).
2. Very little is known about the behaviour of early Homo sapiens, so hypotheses about this are just that - purely hypothetical.
3. Evolutionary arguments can easily underestimate the role of culture and cultural evolution as a factor in the development of human behaviour.