valuable reward in the long-term.

In a 2005 study, common marmosets and cottontop tamarins chose between taking an immediate small reward and waiting a variable amount of time for a large reward. Under these conditions, marmosets waited significantly longer for food than tamarins. This difference cannot be explained by life history, social behaviour, or brain size. It can, however, be explained by feeding ecology: marmosets rely on gum,