In a family study, researchers are able to examine the extent to which a trait runs or goes together in intact families. Intact families are families where all members have lived together for a duration of their life. Francis Galton studied family studies and he conducted the first family study. Galton discovered that a very smart individual had many first-degree relatives that were also very smart, but fewer second and third degree relatives that were that intelligent. Research has shown that there is a .5 correlation of IQ between brothers and sisters raised in the same family, but only .15 correlation of IQ between cousins. This finding proves that there is a positive correlation with IQ and families. This is interesting because it shows how an environment which you are raised in or even genetics may affect ones IQ.
This applies to my life because even though it has not been tested, I believe that I have a very similar IQ to my brother. My brother and I both were raised together, in the same environment for our entire life. We now both attend the U of M. My brother and I had very similar high school GPA's and ACT scores. This is interesting to me because I think its crazy that two separate people can have such similar intelligence. We were raised in the same environment and have the same genetics so it is evidence that IQ runs within families.
I used the Psychology text book, page 337 to research this topic