Importance of Heredity in Development - Environment's Role in Human Development

Human development is influenced by both heredity (nature) and environment (nurture). The discussion is about how much of our intelligence, personality, and behavior comes from our genes and how much from our experiences and environment.

Freeman’s Study (Chicago University, 1925)

• Purpose: To study the role of the home environment in children’s mental development.
• Finding: Home environment strongly affects mental abilities.
• Conclusion: The environment clearly influences, though heredity still matters.

Burks’s Study (Stanford University, 1928)

• Purpose: To understand how environment and heredity work together.
• Finding: Both heredity and environment are important for building intelligence.
• Agreement:
• Heredity gives a foundation for ability.
• The environment improves or limits that ability.
• The Chicago group emphasized environment slightly more than heredity.

John B. Watson’s Famous Claim

“Give me a dozen healthy infants... and I will train any one of them to become any type of specialist I might choose—doctor, artist, thief—regardless of abilities or ancestry.”

• Watson, a behaviorist, believed that the environment decides who we become.
• He thought training and learning could shape anyone into anything.
• Modern psychologists call this an extreme view because heredity also affects intelligence and talents.

Conclusion:
The environment is powerful, but genes set certain limits.

• Heredity provides potential (what you can become).
• The environment decides achievement (what you become).
• Exclusive focus on either side is incomplete.

Example:
A child may have good genes for intelligence, but without good education and opportunities, that potential won’t be fully developed.

Human Development = Heredity × Environment

Jensen’s Research

• Found that about 80% of intelligence is hereditary and 20% affected by environment.
• Later, scientists agreed that the environment plays a greater role than Jensen believed.
• Example: Education and enriched upbringing can raise IQ scores, showing the environment’s strong effect.

Adoption and Twin Studies

• Identical twins raised apart show similar intelligence, proving genes are important.
• However, differences also appear because environments differ.
• Adopted children resemble biological parents in potential, but adoptive parents in habits and behaviour.

Why First 5–7 Years Matter?

• The brain develops rapidly in early years.
• Experiences during this period shape personality and intelligence.
• A supportive, loving home builds emotional stability and social confidence.

Whiting and Child’s Study (1953)

• Studied child-rearing across many cultures.
• Found that early parent-child relationships affect personality growth.
• Warm, caring environments support mental and emotional health.
• Uneducated or neglectful parenting causes adjustment problems.

Freud’s View

• Early emotional experiences play a permanent role in personality development.
• Positive early relationships lead to a healthy, confident personality.

• Enriched environment: education, love, support → better growth.
• Restricted environment: neglect, lack of learning, → poor development.
• The socio-economic conditions of parents affect educational access, diet, and motivation, which in turn influence the child’s growth.

Examples:

• Special training can help children with disabilities (e.g., speech therapy for children with hearing impairments).
• Proper education and training reduce hereditary limitations.

• Heredity and environment interact continuously. One cannot be separated from the other.
• Neither factor can work alone.
• Modern science rejects extreme views and supports a combined approach.

• Both heredity and environment are essential for development.
• Heredity sets the limits; the environment decides the outcome.
• Early childhood care and education are extremely important.
• Good parent-child relationships support healthy growth.
• Education, nutrition, and motivation can improve performance.
• Training and supportive environments reduce genetic disadvantages.
• Positive environment = better development; negative environment = limited growth.