Straight Talk about Twin Studies, Genes, and Parenting: What Makes Us Who We Are

http://www.psychologytoday.com/blog/beautiful-minds/200810/straight-talk-about-twin-studies-genes-and-parenting-what-makes-us-who-w

The article explains how although people argue that environments change how twins act and their level of intelligence and personality, at the end of the day it comes down to genetics. It turns out that genetic variation is correlated with the variation in environments. According to the article people engage in in certain environmental experiences based on their genetic make up and the environment thus reciprocates reinforcing the individuals nature. Therefore, David Moore and Scott Barry Kaufman wrote a book that had eight facts about genes and twin studies. The facts are as follows: 1. Genes cannot determine anything themselves In reality, all biological and psychological characteristics are constructed during development, when genes interact with local environmental factors that can be influenced by the broader environment. 2. Parents matter, and will always matter: The parenting factors that are statistically associated with differences between individuals should never be confused with the parenting factors that cause the development of a trait within an individual. 3. Heritability depends entirely on context: both are always contributing to the development of any trait, and context matters. 4. The actual heritability value simply does not matter because the development of behavioral/psychological characteristics can be influenced by experiential factors in ways that are unpredictable from casual observation. 5. Heritability doesn't necessarily have to do with biology: the least heritable features of human nature may be those that appear to be the most genetically determined.6. Heritability says nothing about whether intelligence is more determined by genes or the environment:  Because heritability is a population statistic, it has nothing to say about the individual. 7. Twin Studies do not reveal the causes of intellectual development: Because adoption and twin studies that seek to account for trait variation in terms of genetic and environmental variation are always correlational, they reveal nothing about the causes of the appearance of the traits. and 8. Heritability is not the same as heredity: Because traits that are 100% heritable can nonetheless be strongly influenced by environmental factors, it is not the case that a trait found to be heritable in a particular twin study will be passed from a given pair of parents to their children.