Passage Three
Most people are right-handed and children usually have the same handedness as their parents. This suggests that genes are at work. But identical twins have identical genes, so genes cannot be the whole story. Cultural attitudes seem to have played an important part in the development of hand preferences. In the past, left-handed have suffered anything from teasing to flogging. Even today in some countries en forced right-handedness, particularly for writing and eating, is still common.
To explain the observed patterns of handedness, researchers have devised what is known as a’ geneculture coevolution’ model. The initial assumption of the model-drawn from observation of non-human primates and other mammals such as mice-is that early on in human evolution, the genetic make-up of individuals inclined them to prefer one hand or the other, but that the population was equally divided between right and left-handed people. Over time, accor
A. handedness is solely determined by genes
B. handedness is solely determined by culture
C. handedness is determined by both genes and culture
D. handedness may be determined by factors other than genes and culture
我来回答: