Nature vs nurture

Heredity and the environment

Generally, the various factors influencing the development of our psychological characteristics can be classified into one of two broad areas: heredity (nature) and environment (nurture).

Nature vs nurture

Interaction of hereditary and environmental factors in shaping psychological development

Research methods for studying lifespan development:

Longitudinal, twin and adoption studies

Developmental psychology from different perspectives

Biological perspective - focuses on how heredity and biological factors influence the development of psychological characteristics. Behavioural perspective - focuses on how behaviour is acquired or changes as a result of environmental influences, particularly learning. Cognitive perspective - focuses on changes in how we acquire, process, remember and use information throughout the lifespan. Socio-cultural perspective - focuses on the effects of specific environmental factors such as gender, age, race, income and culture on human behaviour and mental processes.

Cross-sectional study

Selects and compares groups of participants of different ages over a short period of time. It is a relatively inexpensive and less time-consuming alternative to the longitudinal study but can be affected by generational influence.

twin studies

Studies of monozygotic twins (one fertilized egg that splits in two) can provide valuable information because any differences which develop between them can be attributed to differences in their upbringing and experiences (environment). When 24,000 pairs of identical twins were compared on two personality traits (extroversion and neuroticism) the results showed identical (monozygotic twins) living in the same environment were more alike on these characteristics than fraternal (dizygotic) twins. This shows heredity plays a significant role in the development of these characteristics.

Longitudinal studies

A longitudinal study is a long-term investigation that follows the same group (or groups) of people over an extended period of time, observing and changes in their thoughts, feelings and/or behaviour that occur at different ages. It is a useful way of examining consistencies and inconsistencies in behaviour over time (e.g. whether memory declines with age)

Heredity (nature)

Involves the transmission of characteristics from biological parents to their offspring via genes at the time of conception. Psychological characteristics such as intelligence and personality have a genetic component and are therefore influenced by heredity. Schizophrenia, depression and drug addiction have been linked to changes in brain chemistry and brain functioning that are partially genetically determined. Having a parent with schizophrenia does not automatically mean their offspring will inherit this disorder, but they will have an increased likelihood of developing it.

The nature vs nurture debate

The 'Nature' argument Every aspect of our psychological development is determined by our genes. Social skills, musical ability, personality and even intelligence are inherited. Who we will become is 'locked in' by our genes at the time of conception. The 'Nurture' argument Who we become is determined by our environment and all of our experiences. The development of all thoughts, feelings and behaviours could be explained in terms of a person's learning throughout their life.

Nature AND Nurture

Over time, research evidence has shown it is neither one nor the other that is solely responsible for shaping development - both hereditary and environmental factors interact to shape human development. It's generally agreed our individual development begins with genetic 'instructions' we inherit from our parents that provide the building blocks for our psychological development. The environment interacts with our inherited potential to determine how the genetic plan unfolds.

Adoption studies

Psychologists also use information from research with children who have been adopted, and therefore have no genetic similarity to their adopted parents to learn about the influence of heredity and environment on development. Studies of adopted children have provided support for the view that inheritance (heredity) plays a significant role in an individual's intelligence.

schizophrenia

Schizophrenia is a mental illness that is characterised by perceptual, emotional and intellectual distortions and loss of contact with reality. When one non-identical twin is diagnosed with schizophrenia, the other twin will be diagnosed about 17% of the time. When one identical twin is diagnosed, the other has a 48% chance of being diagnosed. The rate is not 100% as you would expect if schizophrenia was entirely due to genetic forces. While the rate is higher for identical than non-identical twins, environmental influences are obviously very important.

Environment (NuRture)

The experiences, objects and events to which we are exposed throughout our entire lifetime. Includes: whether you have brothers and sisters how you are brought up your friendship groups, schooling your religion and ethnic origins occupation and income level whether you have a partner whether you experience a major stressful life event other personal and socio-cultural factors