Two experiments investigated the proclivity of 14-month-old infants (a) to altruistically help others toward individual goals, and (b) to cooperate toward a shared goal. The infants helped another person by handing over objects the other person was unsuccessfully reaching for, but did not help reliably in situations involving more complex goals. When a programmed adult partner interrupted a joint cooperative activity at specific moments, infants sometimes tried to reengage the adult, perhaps indicating that they understood the interdependency of actions toward a shared goal. However, as compared to 18- and 24-month-olds, their skills in behaviorally coordinating their actions with a social partner remained rudimentary. Results are integrated into a model of cooperative activities as they develop over the 2nd year of life.