Erikson, Piaget & Psychology Theories & Concepts Explained

Inner Speech: Vygotsky’s Theory of Thought and Language Development

Inner speech is the silent, internal dialogue that runs through your mind as you plan, reason, and regulate your emotions — and according to Lev Vygotsky, it doesn’t emerge spontaneously. It develops through a systematic process rooted in social interaction, gradually moving inward through childhood. In his landmark work on lev vygotsky thought and language, Vygotsky argued that language doesn’t...

Harlow’s Monkey Experiment: Why Baby Monkeys Chose Touch Over Food

Harlow’s monkey experiment was a landmark series of studies conducted by psychologist Harry Harlow in the 1950s that proved infant attachment is driven by contact comfort—the need for physical touch—not by feeding. Baby rhesus monkeys given a choice between a wire surrogate that provided milk and a soft cloth surrogate that provided none spent up to 18 hours a day...

Erikson’s Stages of Psychosocial Development: All 8 Stages, Virtues & Life Examples

Erikson’s stages of development describe eight turning points that unfold from birth to old age. Each stage presents a central conflict — resolve it well, and you gain a lasting psychological strength called a virtue; struggle with it, and those tensions resurface in later stages. Real-life examples from every phase of life — toddlers asserting independence, teenagers wrestling with identity,...

Cognitive Dissonance Theory: Festinger’s Model & Reduction Strategies

Why do smokers rationalize their habit despite knowing it causes cancer? Why do we justify expensive purchases we later regret? Why do people invested in failing relationships convince themselves everything is fine? Leon Festinger’s cognitive dissonance theory, introduced in 1957, explains these behaviors through one powerful insight: holding contradictory beliefs, attitudes, or behaviors creates psychological discomfort that we are motivated...

Prosocial Behavior and Altruism: Definition, Examples & Key Theories

Prosocial behavior is any voluntary action intended to benefit another person or group — whether that means sharing lecture notes with a classmate, donating to a disaster relief fund, or pulling a stranger out of harm’s way. It sits at the center of how psychology understands cooperation, empathy, and moral motivation. While it’s tempting to assume people are naturally inclined...

Theories of Emotion: James-Lange, Cannon-Bard & Schachter-Singer Explained

When you stumble across a bear on a hiking trail, your heart races, your palms sweat, and fear grips you all at once. But which came first — the racing heart or the feeling of fear? This seemingly simple question sits at the center of psychology’s most influential theories of emotion. Over more than a century, three major frameworks —...