Science Scoops: Does Having Boys or Girls Run in the Family?

Let's say you are a girl who comes from a family of all girls. Does that mean that you, too, have a high probability of bringing a girl into the world? No. In fact, statistical theory suggests otherwise. According to Chance magazine (published by the American Statistical Association), there is no compelling evidence to suggest that family history plays a role in whether a family has male or female children.

The fact is, statistically, around one-eighth of all four-child families are expected to be all-male or all-female under a chance model. And it's possible, statistically, for families of up to 10 children to be all of the same sex. There is no evidence that having boys (or girls) has either genetic or shared environmental sources of influence.

Vocabulary

  • genetic: Of or relating to the branch of biology that deals with how characteristics are passed from parents to offspring.
  • statistical: Relating to a collection or set of numbers, facts, or other data.

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there is a cartoon of two families, one with all boys and one with all girls

Activity

  1. Based on this article, do you think there is a genetic trait for having boys or girls? Why or why not?