A smile, a frown, a surprised look—such facial expres-
sions convey powerful socio-emotional dispositions. In-
deed, facial expressions often foreshadow, amplify, and
even supersede verbal communication (see Ekman, 1993).
Both psychological and neurocognitive findings suggest
multiple processes involved in the reception, encoding,
recognition, and elicitation of facial expressions (for re-
views, see Adolphs, 2002; Posamentier & Abdi, 2003).
Moreover, ever since Darwin’s treatise on emotional ex-
pressions (Darwin, 1872), it has been recognized that fa-
cial expressions are to a substantial degree universal and
common across cultures.
With respect to the encoding of facial expressions, some
findings suggest a greater impact of negative expressions
(e.g., anger or fear) as opposed to positive ones (e.g., happy
or perhaps surprise). For example, the so-called face-in-the-
crowd effect suggests that angry faces are detected faster
than happy faces when they are presented within an array
of other faces (Fox et al., 2000; Hansen & Hansen, 1988).
Also, negative expressions interfere when performance re-
quires processing of facial characteristics unrelated to the
expression (Eastwood, Smilek, & Merikle, 2003). Such in-
terference effects suggest that attentional focus is directed
to negative expressions, and as a result, the processing of
other stimulus features is compromised.
From a sociobiological perspective, the ability to rec-
ognize angry or threatening expressions would be highly
advantageous, for survival could depend on an animal’s
ability to encode and react to such displays. Positive
expressions, such as happy or surprise, also convey in-
formation important for selection, such as kinship or a
willingness to mate. Some studies have suggested a pro-
cessing advantage for positive expressions over negative
ones. Kirita and Endo (1995) showed that reaction time
to judge whether a face was happy or sad was faster for
happy faces. Such studies have generally used schematic
drawings of face