Which of the following provides some evidence that there is, in fact, a genetic component to handedness?
A) Between monozygotic twins, the likelihood that both children have the same dominant hand is no greater than between fraternal twins or non-twin siblings.
B) As teachers have stopped encouraging children to use their right hands, the percentage of left-handed children has risen.
C) Societies have favored right-handed people in their design of common objects, such as scissors, can-openers, and school desks.
D) The part of the brain that controls handedness, the substantia nigra, develops more fully in right-handed children than in left-handed children.

Question

Which of the following provides some evidence that there is, in fact, a genetic component to handedness?
A) ​Between monozygotic twins, the likelihood that both children have the same dominant hand is no greater than between fraternal twins or non-twin siblings.
B) ​As teachers have stopped encouraging children to use their right hands, the percentage of left-handed children has risen.
C) ​Societies have favored right-handed people in their design of common objects, such as scissors, can-openers, and school desks.
D) ​The part of the brain that controls handedness, the substantia nigra, develops more fully in right-handed children than in left-handed children.

Quizplus · Accepted Answer

B) indicates a change in the prevalence of left-handedness when external pressures (such as teaching practices) change, suggesting an underlying predisposition that can be expressed when not suppressed, hinting at a genetic component.

Which of the Following Provides Some Evidence That There Is