Children born blind or deaf and blind begin social smiling on roughly the same schedule as most children, by about three months of age.

The information above provides evidence to support which of the following hypotheses?

We are given: Despite the sensuous differences, most children begin social smiling at roughly the same age. This tells us that the schedule is independent of the organs functioning capabilities. If these findings were true, then this development could occur innately.


(A) For babies, the survival advantage of smiling consists in bonding the caregiver to the infant.

It may be true, but it doesn't answer why blind or deaf kids learn to smile at about the same time as the kids with no organ deficiency.

(B) Babies do not smile when no one else is present.

The evidence actually undermines this hypothesis. If this were true, then deaf or blind kids smiling development would have differed from those of kids with no organ deficiency.

(C) The smiling response depends on an inborn trait determining a certain pattern of development.

If smiling response points to some innate or natural human characteristic that is independent of any organ functionality, then the evidence supports this hypothesis. Because, if all kids learn to smile roughly at the same time, then this development would be considered innate.

(D) Smiling between persons basically signals a mutual lack of aggressive intent.

The evidence doesn't support this hypothesis by no means. All the evidence is suggestive of the time frame of social smiling development. There is no information mentioned regarding any behavior.

(E) When a baby begins smiling, its caregivers begin responding to it as they would to a person in conversation.

This may be true, but the finding doesn't support this hypothesis in any manner.

C is the best answer.