INFPs at School
Keirsey (1998) has noted that teachers much enjoy their INFP students, who are among the most positive and affirming members of the class. (However, if the teacher assigns academic weight to classroom participation, the INFP's grades may suffer since they prefer to remain quietly in the background.)
INFPs consistently come up as third or fourth most likely type to be assigned the "gifted" label and receive high aptitude scores (Myers et al., 1998). They also come up as the fourth or fifth type mostly likely to receive high grades.
A very small study of language learners found that those with the preferences I, N, F, and P get better grades in foreign language courses in college (Ehrman & Oxford, 1990). Note, however, that preference trends are not the same as an actual type; Ehrman & Oxford's study actually included only two INFPs. You can read the entire study here. Moody (1988) found that there were 1.42 times as many INFPs as would be expected in a group of first and second year language students. You can read the whole study here.
Unfortunately, college is an unhappy time for many INFPs; they are the most likely of all types to report suicidal thoughts during this period (Komisin, 1992). A study also found that they were among the top two most frequent violators of a school's alcohol policy (Barrineau, 1997).
ADD Misdiagnosis Risk
It has been suggested that INFPs are at risk for being misdiagnosed with ADD (non-hyperactive version) in school due to their natural tendencies, i.e. "dreaminess," the preoccupation with their rich inner world; the fact that they are Perceivers and therefore not particularly organized or punctual; and the fact that they are Intuitives and not interested in what they see as the "minor" little details. (I suspect that their high overrepresentation among the gifted population also contributes to misdiagnoses, since the too-slow pace of the class encourages boredom and escapism.)