Psychology is the study of the mind and behavior, by observing how biological influences, social pressures, personality and environmental factors that affect how people think, act, and feel. Psychologists work with individuals, couples, and families to help them make desired changes to behaviors. The four main goals of psychology are to describe, explain, predict and change the behavior and mental processes of others. Describing a behavior enables the development of general laws of human behavior. ‘Explain’ is how or why the behavior occurs. ‘Predict’ means to foresee future behavior. ‘Change’ means to control a behavior. Psychology has many sub-fields, which include Abnormal psychology – the study of abnormal behavior and psychopathology; Biological psychology (biopsychology) – how biological processes influence the mind and behavior. Clinical psychology – assessment, diagnosis, and treatment of mental disorders; Cognitive psychology – study of human thought processes including attention, memory, perception, decision-making, problem-solving, and language acquisition; Comparative psychology – the study of animal behavior; Developmental psychology – study of human growth and development over the lifespan including cognitive abilities, morality, social functioning, identity; Forensic psychology – using psychological research and principles in the legal and criminal justice system; Industrial-organizational psychology – using psychological research to enhance work performance and select employees; Personality psychology – how personality develops as well as the patterns of thoughts, behaviors, and characteristics that make each individual unique; Social psychology – group behavior, social influences on individual behavior, attitudes, prejudice, conformity, aggression. Applications of psychology include developing educational programs, ergonomics, informing public policy, social program design, psychological research, and mental health treatment.