Social Influence on Behavior
Social influence shapes how we act in nearly every situation. The roles we fill, the unwritten rules we follow, and the mental "scripts" we rely on all guide our behavior, often without us even noticing. Sometimes these influences are so strong that people act in ways they'd never expect of themselves.
Social Roles
A social role is a set of expected behaviors tied to a specific position within a group. Think of it like a job description for your place in society.
There are two main types:
- Achieved roles are earned through effort or skill (doctor, athlete, class president)
- Ascribed roles are assigned based on characteristics you don't choose (age, gender, race)
Once you step into a role, its expectations start shaping your behavior. A person who becomes a team captain starts acting more assertive. A new employee follows workplace norms they wouldn't have cared about a week earlier. The role pulls behavior toward what's expected.
Two common problems come up with roles:
- Role conflict happens when the expectations of two different roles clash. A working parent might face pressure to stay late at the office while also needing to pick up their child from school.
- Role strain happens within a single role when its demands are excessive or contradictory. A manager asked to cut costs and boost employee morale at the same time is experiencing role strain.

Social Norms
Social norms are the unwritten rules that guide behavior within a group or society. Nobody hands you a rulebook, but you learn them quickly through observation and feedback.
Norms come in two flavors:
- Prescriptive norms tell you what you should do (hold the door, say "please" and "thank you," dress appropriately for the occasion)
- Proscriptive norms tell you what you shouldn't do (don't steal, don't cut in line, don't talk during a movie)
Why do people follow these rules? Two key mechanisms explain conformity to norms:
- Informational social influence occurs when you look to others because you believe they have better information. If you're lost in a new city, you follow where the locals walk. You're conforming because you genuinely think they know something you don't.
- Normative social influence occurs when you conform to fit in or avoid disapproval. Dressing similarly to your peers or laughing along with a group joke you didn't find funny are both examples. Here, the motivation is social acceptance, not accuracy.
Deviance refers to behavior that violates social norms. The consequences depend on which norm is broken and the context. A minor etiquette slip might earn a disapproving glance, while criminal behavior leads to legal punishment.

Scripts
Scripts are mental blueprints for how events typically unfold in familiar situations. You carry one for ordering food at a restaurant, greeting someone new, or attending a job interview.
Scripts reduce cognitive load. Instead of figuring out every interaction from scratch, you follow a pre-set sequence of behaviors. You know when to applaud at a concert, when to shake hands at a meeting, and when to stop talking during a lecture.
Problems arise when scripts break down:
- Deviating from a script can cause confusion or social awkwardness. Showing up in casual clothes to a formal event disrupts what everyone else expects.
- Cultural differences in scripts can lead to misunderstandings. Personal space norms, greeting rituals, and conversational turn-taking all vary across cultures. When people from different backgrounds interact, their scripts may clash without either person realizing why.
Ethical Considerations in Social Psychology Research
Zimbardo's Stanford Prison Study
The Stanford Prison Study (1971) is one of the most famous and controversial experiments in psychology. Philip Zimbardo designed it to investigate how social roles and perceived power affect behavior.
Here's what happened:
- College student volunteers were randomly assigned to play either "guards" or "prisoners" in a simulated prison set up in a Stanford University basement.
- Within days, participants deeply internalized their assigned roles. Guards became increasingly authoritarian and abusive. Prisoners showed signs of severe emotional distress, helplessness, and breakdown.
- The study was originally planned for two weeks but was shut down after just six days because the situation had deteriorated so badly.
The study powerfully demonstrated how quickly social roles can override individual personality. It also highlighted the potential for abuse of power in institutional settings like prisons and the military.
However, the study raised serious ethical concerns:
- Participants experienced significant psychological distress and potential long-term harm
- Informed consent was inadequate because participants weren't fully warned about the risks they'd face
- Zimbardo himself took on the role of "prison superintendent," which meant he was both running the experiment and participating in it. This dual role likely influenced the study's outcomes and delayed his decision to stop it.
It's also worth noting that later analyses have questioned the study's scientific validity. Some evidence suggests guards were coached to be harsh, and some participants may have been acting rather than genuinely conforming. The study remains important for the ethical debate it sparked, even as its findings are viewed more critically today.
The fallout from this study (along with other controversial research of the era) led to stricter protections for research participants:
- Institutional Review Boards (IRBs) were established to review research proposals before studies begin, ensuring ethical standards are met
- Modern research ethics require informed consent, the right to withdraw at any time, minimization of risk, and thorough debriefing after participation