Question 8

Left-handed people tend to have brains that are less strongly lateralized than right-handed people.

This statement accurately reflects research findings that suggest left-handed individuals often exhibit a different pattern of brain lateralization compared to their right-handed counterparts.

A) Dizygotic twins are more likely than nontwin siblings to have the same hand preference.

This option is incorrect because studies indicate that while genetics play a role in handedness, dizygotic twins do not show a significantly higher concordance for handedness compared to nontwin siblings. Environmental factors also contribute to hand preference, making this statement misleading.

B) Left-handed people tend to have brains that are less strongly lateralized than right-handed people.

This statement is correct and supported by neurological research, which shows that left-handed individuals often utilize both hemispheres of the brain more evenly, leading to less lateralization compared to right-handed individuals, who typically show stronger lateralization in the left hemisphere for language and motor functions.

C) Rates of left-handedness are uniform across cultures.

This option is incorrect as rates of left-handedness vary significantly across different cultures and societies. Cultural attitudes and practices can influence the expression of handedness, leading to inconsistent prevalence rates globally.

D) Children do not exhibit a hand preference until the age of seven.

This statement is misleading; children often show preferences for one hand or the other as early as 2 to 3 years of age. While some children may develop a clear preference later, many do demonstrate hand preference much earlier than age seven.

E) Hand preference is determined by genes and not environment.

This statement is overly simplistic and incorrect. Research indicates that both genetic and environmental factors influence handedness, suggesting that it is a complex trait rather than solely determined by genes.

Conclusion

Option B is the most accurate statement regarding handedness, highlighting the neurological differences between left-handed and right-handed individuals. The other options fail to capture the nuances of handedness, whether by oversimplifying genetic influences, misrepresenting cultural variations, or inaccurately describing the development of hand preference in children.