12.7 Prosocial Behavior — Your Brain's Hidden Social Ledger Explained | Psychology 2e

• Understand how an unconscious economic ledger influences social interactions and relationships.
• Explore altruism, defined as selfless help, and the debate on its true motivation.
• Learn how proximity, shared traits, and perceived attractiveness influence relationship formation.
• Understand Sternberg's theory of love, requiring intimacy, passion, and commitment for consummate love.
• Discover how social exchange theory explains relationship longevity through a cost-benefit analysis.
• Consider how advanced AI companions might alter the future of human romantic relationships.
• Up next in “Psychology 2e — Full Course (OpenStax) | Intro Psychology Lectures”13.1 What Is Industrial and Organizational Psychology — Workday As Architecture | Psychology 2e

Why do we risk everything for a stranger, yet carefully calculate who we let into our inner circle? This lesson from Section 12.7 of OpenStax Psychology 2e explores prosocial behavior — from acts of pure altruism to the surprisingly economic logic behind who we befriend, fall for, and stay with. Using real examples and classic psychological theories, the lesson unpacks the hidden math driving our most human connections. In this video: • Altruism defined — including a striking real-world example from the 9/11 World Trade Center attacks • The empathy vs. egoism debate: is any good deed truly selfless, or are we always serving our own ego? • Proximity and homophily as the two biggest drivers of friendship formation — and why homophily can trap us in homogeneous bubbles • The matching hypothesis: why we tend to pursue romantic partners we see as our equals in attractiveness • Sternberg's Triangular Theory of Love and the three components — intimacy, passion, and commitment — needed for consummate love • Social exchange theory: how we act as 'naïve economists,' constantly weighing relationship benefits against costs #OpenStax #Psychology #ProsocialBehavior #SocialPsychology #Altruism OpenStax Content adapted from "OpenStax Psychology 2e", by OpenStax licensed under CC BY 4.0. Content based on Web Version: Apr 23, 2026. Read the textbook online https://openstax.org/details/books/psychology-2e Music first girl talking to me. by ikkun (ex. Barradeen) | https://soundcloud.com/ikkunwastaken Royalty Free Music by https://www.free-stock-music.com Creative Commons / Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0) https://creativecommons.org/licenses/by-sa/3.0/deed.en_US