The Timeline

Textbooks give you landmark studies as a scattered pile of names and dates. Put them on a single line and something clicks: the field keeps changing the question it's obsessed with. First it asked whether other people's presence changes us. Then how far we'll bend to a group or an authority. Then why we sometimes help and sometimes don't. Then how the mind thinks the social world into being. And lately — humblingly — whether the classics were even true. Read down the line and watch the center of gravity move.

The founding: presence and crowds (1890s–1930s)

The field opens with a small, almost quaint question — does having other people around change what you do? — and slowly gets the tools to measure it.

• 1897 Triplett — social facilitation. Cyclists rode faster with others present; children wound fishing reels quicker in pairs. Usually counted as the first social-psychology experiment. See History.
• 1908 McDougall & Ross — the first textbooks. Two books titled Social Psychology appear the same year, one by a psychologist, one by a sociologist — the field is officially born (and immediately claimed by two parents).
• 1924 Allport — Social Psychology. Floyd Allport insists the discipline be experimental and centered on the individual in a social context — the template modern social psych still follows.
• 1928 Thurstone — attitudes can be measured. "Attitudes can be measured": Thurstone builds the first rigorous scaling method, turning a fuzzy inner state into a number. The measurement problem cracks open. See Attitudes.
• 1934 LaPiere — attitudes vs. behavior. A Chinese couple was served at nearly every hotel and restaurant they visited, though most later said in writing they'd refuse. What people say and what they do come apart — a problem the field is still chewing on.
• 1935 Sherif — norm formation (autokinetic effect). In a dark room a still point of light seems to drift; strangers' estimates converge into a shared "norm" they keep even alone. Conformity built from nothing. See Conformity.

The situationist era (1930s–1970s)

After WWII the field asks the question that would define it: how far will ordinary people bend to a group, an authority, or a role? The answers were disturbing — and made social psychology famous.

• 1930s–40s Lewin — field theory, B = f(P, S). Kurt Lewin, "father of modern social psychology," frames behavior as a function of the Person and the Situation, founds group dynamics, and coins "nothing so practical as a good theory." See History.
• 1950 Festinger, Schachter & Back — proximity builds friendship. In a married-student housing complex, the floor plan predicted who became friends: next-door neighbors and people near stairwells collected the most friendships. The seating chart as matchmaker. See Attraction.
• 1951 Asch — conformity to a wrong majority. On an obvious line-length task, people conformed to a unanimous but plainly wrong group on about a third of trials. See Conformity.
• 1954 Festinger — social comparison theory. We evaluate our own abilities and opinions by comparing ourselves to others — especially when there's no objective yardstick. The engine behind envy, status, and much of social media.
• 1957 Festinger — cognitive dissonance. Holding two clashing cognitions is aversive, so we change an attitude to relieve the tension — the famous $1-vs-$20 study. See Dissonance.
• 1958 Heider — attribution theory. People are "naïve scientists," constantly inferring the causes of behavior — internal disposition vs. external situation. See Attribution.
• 1961 Bandura, Ross & Ross — the Bobo doll. Preschoolers who watched an adult batter an inflatable clown reproduced the attacks move for move — aggression learned by pure observation, no reward required. See Aggression.
• 1963 Milgram — obedience to authority. 65% of ordinary adults delivered what they believed was a 450-volt shock because an authority told them to continue. See Obedience.
• 1966 Walster et al. — the computer dance. Students randomly paired for a dance; of everything measured, only physical attractiveness predicted wanting a second date. What we say we want and what moves us diverge. See Attraction.
• 1967 Jones & Harris — the fundamental attribution error. Readers assumed an essay reflected the writer's true opinion even when told a coin flip assigned the position — we over-credit disposition, ignore the situation. See Attribution.
• 1968 Zajonc — the mere exposure effect. Simply seeing a stimulus repeatedly — a face, a word, a symbol — increases liking for it, no interaction required. One of the field's sturdiest findings. See Attraction.
• 1968 Darley & Latané — the bystander effect. The more witnesses to an emergency, the less likely any one person helps — diffusion of responsibility. Sparked by the Kitty Genovese case. See Prosocial Behavior.
• 1968 Rosenthal & Jacobson — the self-fulfilling prophecy. Teachers told (falsely, at random) that certain pupils were "bloomers" — and those children's scores actually rose. Expectations shape reality. See Social Cognition.
• 1971 Tajfel — minimal group paradigm. Even meaningless, arbitrary group labels were enough to make people favor "us" over "them." In-group bias needs almost nothing to ignite. See Prejudice.
• 1971 Zimbardo — Stanford Prison "Experiment." Assigned prisoner/guard roles seemed to breed rapid cruelty — but read this one critically; it did not hold up as told. See Science Corrects Itself.
• 1973 Darley & Batson — the Good Samaritan study. Seminary students on their way to preach on the Good Samaritan stepped over a slumped stranger — if they'd been told they were late. Situation beat character and even sermon topic. See Prosocial Behavior.

The cognitive turn (1970s–1990s)

The wider "cognitive revolution" arrives: the field stops asking mainly what situations do and starts asking how the mind processes the social world — its shortcuts, its biases, its motivated stories.

• 1974 Tversky & Kahneman — heuristics and biases. The mind judges probability with fast mental shortcuts (availability, representativeness, anchoring) that misfire in predictable ways. See Heuristics.
• 1974 Dutton & Aron — the shaky bridge. Men interviewed by an attractive researcher on a fear-inducing suspension bridge were likelier to call her later — arousal from fear misread as attraction. Misattribution of arousal, in the field. See Attraction.
• 1977 Ross — naming the fundamental attribution error. Lee Ross gives the disposition-over-situation bias its enduring label and shows just how deep the trap runs. See Attribution.
• 1980s Petty & Cacioppo — the Elaboration Likelihood Model. Persuasion runs on two routes: the effortful central route (weighing arguments) and the lazy peripheral route (cues like attractiveness). See Attitudes.
• 1980s–90s Greenberg, Pyszczynski & Solomon — Terror Management Theory. Reminders of our own death push us to cling harder to worldviews and self-esteem — a buffer against mortal dread. See Terror Management.
• 1991 Markus & Kitayama — culture and the self. Independent vs. interdependent self-construals show that "basic" findings from Western labs don't always travel — the WEIRD-samples problem, foreshadowed.
• 1995 Steele & Aronson — stereotype threat. Merely making a negative stereotype salient depressed the test performance of the stereotyped group. Identity in the room changes the score. See Prejudice.

Brain, culture, and the reckoning (1990s–now)

The field pushes outward — into the brain, into implicit cognition, across cultures — and then turns a hard, healthy eye on itself: which of these famous findings actually replicate?

• 1996 Bargh, Chen & Burrows — automaticity and priming. Words like "elderly" seemed to slow people's walking; social behavior can run on autopilot. (A cornerstone claim that the replication era later put to the test — see below.)
• 1998 Greenwald, McGhee & Schwartz — the Implicit Association Test. A reaction-time task claiming to measure attitudes people won't (or can't) report. Launched a whole industry — and a long fight over what it means. See Prejudice.
• 2002 Bushman — catharsis backfires. Angered people who hit a punching bag while ruminating on their provocateur got angrier and more aggressive than people who did nothing. "Venting" rehearses aggression instead of draining it. See Aggression.
• 2003 Neff — self-compassion. Treating yourself with the kindness you'd give a friend — self-kindness, common humanity, mindfulness — enters psychology as a measurable, health-promoting construct. See Compassion.
• 2011 The replication crisis begins. Bem's ESP paper and the "false-positive psychology" critique detonate a credibility crisis; the Open Science movement — preregistration, bigger samples, open data — is born. See Science Corrects Itself.
• 2015 Open Science Collaboration — reproducing 100 studies. A mass replication of 100 psychology findings reproduced fewer than half at full strength. The field's self-audit goes public — and sobering. See Science Corrects Itself.
• 2019 Klein et al. — Many Labs 4. Coordinated multi-lab replications of Terror Management's mortality-salience effect found little support even with the original authors' input — a model for how the field now checks its classics. See Science Corrects Itself.

So when a finding stumps you, place it on this line. Is it a presence question, an influence question, a cognition question, or a does-it-hold-up question? Knowing which act of the story you're in is half the answer — and it's a habit no flashcard can give you.

References

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