Behaviors can be conscious or unconscious and are influenced by a wide range of factors, including :
one’s own attitudes, the attitudes perceived in others, one’s beliefs and values, social norms and laws, the ability to control oneself, disinhibition due to substances, endless repetition of the same situation, biology, genetics, gender, age, sleep deprivation, medication, climate, psychopathy, etc.
Comparison between attitudes and behaviors: see the definition of the word attitude (explanations follow the definition).