Nature-nurture

Nature/nurture debate

• Nature emphasises the influence of genetics and hereditary factors on behaviour

• Heredity is the genetic transmission of mental and physical characteristics from one generation to another

• Nurture emphasises the influence of environmental factors on behaviour

• Environment - any influence on human behaviour that is non-genetic e.g. prenatal infuences in the womb to cultural and historical influences in society

• This is one of the oldest philosophical issues in psychology and continues to be a topic of interest amongst researchers

Relative importance of the debate

• Nature-nurture is impossible to answer because environmental influences in a child’s life begin as soon as they are born, perhaps pre-natally

• In twin studies, it is often difficult to tell whether the high concordance rates are more the result of shared genetics or upbringing

• The focus of the debate has changed in recent years, psychologists more likely to ask what the relative contribution of each influence is in terms of what we think and do

Interactionism

• Nature and nurture are linked to such an extent it makes no sense to separate the two, so researchers instead study how they interact and influence each other

• In attachment, patterns between an infant and its caregivers are often the result of a two-way street, in which the child’s innate temperament will influence the way the caregivers respond to it, and their response will turn affect the child’s behaviour. Thus, nature, in a sense, creates nurture, heredity and the environment interact

Diathesis-stress

• Suggests psychopathology is caused by biological/genetic factors e.g. a diathesis of a faulty C4 gene, which is triggered by environmental factors, like drug abuse, causing schizophrenia

• Tienari et all (2004) found that in a group of Finnish adoptees those most likely to develop schizophrenia had biological relatives with a history of the disorder, and had dysfunctional relationships with their adoptive families

Epigenetics

• Refers to a change in our genetic activity without changing our genetic code. It is a process that happens throughout our life and is caused by interaction with the environment

• Aspects of our lifestyle, and the events we encounter, from smoking and diet to pollution and war, leave epigenetics marks on our DNA

• These marks let our bodies know which genes to ignore and which to use, and in turn, they may go on and influence the genetic codes of our chuldren and grandchildren

Dias & Ressler: Epigenetics

• Gave mane lab mice electric shocks every time they were exposed to the smell of acetophenone, a chemical used in perfume

• As any behaviourists would predict, the mice showed a fear response as soon as the scent was presented

• Surprisingly, the mices’ children also feared the smell, even though they had not been exposed to acetophenone before or received any shocks, so did their grandchildren