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Psychology of Human Growth and Development
cognitive development part 2
Psychosocial development
Development of emotions
Language development
Cognitive development part 1
Perceptual development part 2
Development of attachment
Nature versus nature
Introduction to developmental theories
Prenatal development and chromosomal abnormalities
Prenatal development and teratogens
Brain development
Motor development
Physical growth
Perceptual development

Lecture 2


nature versus nurture


Central question is


how far are human behaviors, ideas, and feelings, innate, and how far are they all learned?


The genetic argument (nature)


Individual behaviour is mainly determined by substantial genetic component.


The societal argument (nurture)


Our social learning processes and our environmental conditions (e.g. stimulation) will determine our individual behaviour and abilities.


Historical Debate of nature versus nurture


John Locke (nurture)

Thomas Hobbes, (nurture)

Ren Descartes, (nature)

Charles Darwin, (nurture)

John Broadus Watson, (nurture)

B. F. Skinner, (nurture)

Arnold Gesell, (nature)

Carl Gustav Jung  (both)

William Sheldon. (nature)


Methods to investigate the nurture / nature debate


Twin studies

Longitudinal studies

Adoption studies

Orphanage life


Support for the genetic argument (nature)


Bouchard et al.


- revealed an extensive range of similarities between identical twins raised together and separately


Bouchard and McGud (1981)


- the higher the proportion of genes two family members have in common the higher the average correlation between their IQ's.


 Plomin, Pedersen, McClean, Nesselroade, and Bergman, (1988).


- influence of heredity on intelligence increases with age



Support for the environmental argument (nurture)


Jense, (1969)


- Many of these adults who had spent all their early life in an orphanage worked at jobs requiring minimum skills. Thus demonstrating the environmental impact on intelligence.


David Layzer's (1976)


- A child grown up in circumstances that provide motivation, reward and opportunity for the acquisition of verbal skills will achieve a higher level of verbal proficiency than his twin reared in an environment hostile to this id of development.

- study indicates that the more relevant a given task is to an individuals specific environmental challenges, the more important are the effects of this interaction.


Freeman (1928)


- In general, the results demonstrate that improved environmental conditions which endure can raise the level of intelligence, if optimal conditions are provided early in life.

- But the amount of improvement is always limited by the mental capacity that was there at birth.



The interaction between nurture and nature


In the Nature Versus Nurture debate, there is, of course, no winner.


Therefore, framing the question as one factor versus the other is misguided.


For any given human trait or behavior, heredity and environment do not compete to see which will win, or which factor will emerge as the singular reason why someone is the way they are. Instead, heredity and environment interact.


Kagan (1979)


- children reared in middle –class American homes begin to speak at about 1 year of age. Children reared in San Marcos a remote village in Guatemala have little verbal interaction with adults and do not utter their first worlds until they are over 2 years old


Recommended reading


Hetherington, E. M. and Parke, R. D (1999) Child Psychology: A contemporary perspective. 5th edition. McGraw Hill: Boston