Motivation, Emotion and Stress
Motivation
Motivation theories include instinct, drive-reduction (homeostasis, primary and secondary drives), arousal (Yerkes-Dodson: moderate arousal optimal, optimum varies with task difficulty), incentive, and Maslow's hierarchy (physiological, safety, belonging, esteem, self-actualisation). Intrinsic motivation arises from interest; extrinsic from external reward; overjustification can undermine intrinsic motivation. Achievement motivation and self-determination theory (autonomy, competence, relatedness) are relevant.
Emotion
Know James-Lange (bodily change then emotion), Cannon-Bard (simultaneous), Schachter-Singer two-factor (arousal plus cognitive label), and Lazarus (appraisal). Basic emotions and facial expression research are commonly cited. Emotion has physiological, cognitive, behavioural, and subjective components.
Stress
Stress is the response to perceived demands exceeding resources. Selye's general adaptation syndrome: alarm, resistance, exhaustion. Lazarus's transactional model emphasises primary appraisal (is this a threat?) and secondary appraisal (can I cope?). Coping is problem-focused or emotion-focused. Chronic stress affects immune, cardiovascular, and mental health.
Traps and rule of thumb
A common trap is attributing the two-factor theory to James-Lange, or claiming Maslow's levels are strictly sequential in all cases. Rule of thumb: if a theory names a cognitive label as necessary, it is Schachter-Singer or Lazarus; if the body comes first, it is James-Lange.