When Mr. Tucker came in to conduct research on the fifth-grade class, he found that Gavin received about the same number of positive ratings and negative ratings by his peers. He would be classified as a(n) child.

Average.

Explanation:

As per the given description, Gavin would be characterized as an 'average child' because the ratings received by his peers both the negative as well as positive reflect the similar numbers which imply that he is neither exceptionally intelligent or intellectual to be liked by all nor extremely dull or dumb to be disliked by all. The 'average children' perform well in various fields however, not spectacular or extraordinarily like 'above average' kids but socially competent enough to perform good and thus, liked by some peers while disfavored by the others. Therefore, 'Gavin' would be considered an 'average' child.