If "basic" means necessary for life, then breathing, eating, drinking and washing are basic human activities. But they hardly pertain only to humans. Nor do they constitute more than a small fraction of all the activities necessary to a full human life. Outlining the whole scope of basic human activities requires a look not only at a person's momentary needs but at how a person changes over a lifetime.

Physiological

Inability to satisfy physiological needs restricts a person's activities.
Inability to satisfy physiological needs restricts a person's activities.

Basic human activities correspond to human needs. Theorist Abraham Maslow proposes that the fulfillment of some needs is predicated on fulfilling others, observes psychologist David G. Myers in his book "Psychology, 6th ed." Physiological needs --- the needs of your body --- are the first to demand attention. If you are starving, notes Myers, you must eat before you can think of anything else. If you are suffocating, you must breathe before you can eat.

Safety

When terrified, you focus on self-defense, sweeping all other activities aside.
When terrified, you focus on self-defense, sweeping all other activities aside.

Only after satisfying your physiological needs can you afford to engage in activities corresponding to other needs. Maslow suggests that the first of these is the need for safety, notes Janet Simons, et al. in "Psychology --- the Search for Understanding." If you fear attacks by burglars, for example, you will not rest until you have taken measures to protect yourself and your property.

Social and Esteem

A full human life requires affectionate relationships and a sense of belonging.
A full human life requires affectionate relationships and a sense of belonging.

Once you feel safe, social needs assert themselves. These, note Simons, et al., comprise needs for love, affection and belongingness. At this level, you might engage in activities such as flirting, dating, joining a club, chatting with neighbors or getting together with co-workers after hours. Once you have made acquaintances, you experience a further need, the need for esteem, notes Myers. This impels you to engage in activities to show colleagues, co-workers, classmates and others that you deserve their respect.

Self-Actualization

Self-actualization is fully realizing your potential, however you conceive it.
Self-actualization is fully realizing your potential, however you conceive it.

The highest level of needs pertains to self-actualization. By "self-actualization," Maslow means living up to your full and unique potential, says Myers. The nature of potential varies from one person to another. For one, it might involve striving to break an Olympic record. For another, it might center on excelling as a gourmet chef. A third might experience herself most fulfilled in nurturing infants and caring for children.

Psychosocial Development

More so than children or adults, adolescents wonder about who they are.
More so than children or adults, adolescents wonder about who they are.

Life consists of eight stages, each marked by a characteristic crisis, according to psychologist Erik Erikson. Adolescence, in Erikson's scheme, forces you to face the question of personal identity, observe Diane Papalia, eta al. in "Human Development, 8th ed." At this stage, you might experiment with different activities, joining a sports team, editing the school newspaper, writing songs for the school play or campaigning for a political candidate. Later, you might blush to think that you took yourself seriously in all those activities. At the time, however, they were basic to your life, helping you figure out who you were and wanted to be.