Page 84 - Biblical Counseling II-Textbook

the evidence: Does sharing the same genes also mean sharing the same mental abilities? The answer is
yes. Identical twins who grow up together have intelligence test scores nearly as similar as those of the
same person taking the same test twice! Even when identical twins are adopted by two different
families, their scores are very similar. Genes matter” (Myers, p. 226, 2012).

“But shared environment matters, too. Fraternal twins, who are genetically no more alike than any
other siblings – but who are treated more alike because they are the same age – tend to score more
alike than other siblings. And studies show that adoption of mistreated or neglected children enhances
their intelligence scores (new environment, intelligence increases). So, should we expect biologically
unrelated children adopted into the same family to share similar aptitudes?” (Myers, p. 227, 2012) For
example, should my adopted sister score about the same as me and my biological siblings on
intelligence tests?

“Seeking to untangle genes and environment, researchers have compared the intelligence test scores of
adopted children with those of their family members. These include their biological parents (the
providers of their genes), their adoptive siblings (who share the same home environment). During
childhood, adoptive siblings’ test scores correlate modestly. What do you think happens as the years go
by and adopted children settle in with their adoptive families? Would you expect the effect of family
environment to grow stronger and the genetic effect to shrink?” (Myers, p. 227, 2012).

“If you said yes, I have a surprise for you. Mental similarities between adopted children and their
adoptive families lessen with age, dropping to roughly zero by adulthood. Similarities with biological
parents become more apparent as adopted children gain life experience” (Myers, p. 227, 2012).

“Your genes and your environment work together. Suppose that you have a natural aptitude for school,
read books, and ask questions – all of which will increase your brain power. In this gene-environment
interactions, small genetic advantages can trigger social experience that multiply our original skills”
(Myers, p. 227, 2012).

11.4. Let’s Practice

1. Define intelligence. How do people in your culture (where you currently live) define
intelligence?

2. Describe how genetic (nature) and environmental (nurture) shaped your intelligence.

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