Young children's early understanding of emotion was investigated by ex
amining their use of emotion terms such as happy, sad, mad, and cry. F
ive children's emotion language was examined longitudinally from the a
ge of 2 to 5 years, and as a comparison their reference to pains via s
uch terms as hum, sting, and hurt was also examined. In Phase 1 we con
firmed and extended prior findings demonstrating that by 2 years of ag
e terms for the basic emotions of happiness, sadness, anger, and fear
are commonly used by children as are terms for such related states as
crying and hurting. At this early age children produce such terms to r
efer to self and to others, and to past and future as well as to prese
nt states. Over the years from 2 to 5 children's emotion vocabulary ex
pands, their discussion of hypothetical emotions gets underway, and th
e complexity of their emotion utterances increases. In Phase 2 our ana
lyses go beyond children's production of emotion terms to analyses of
their conception of emotion. We focus especially on when children use
emotion terms to refer to subjective experiential states of persons. F
rom their earliest uses of these terms in our data children refer to e
motions and pains differently, and distinguish emotions and pains from
the external situations that elicit them. In addition, they evidence
an understanding of emotions as the experiential states of persons, di
stinguished from the actions (e.g. hitting) and expressions (e.g. smil
ing) that emotions cause, and they distinguish between the subjective
emotional experiences of different individuals.