Nudge Wiki

Concept

Attitude-Behavior Gap

Also known as: Attitude-Behavior Inconsistency

attitudes behavior-change public-policy

Conventional marketing wisdom holds that changing someone's attitude toward a product or cause is the necessary first step toward changing their behavior. Phil Barden argues the evidence doesn't support this as reliably as assumed — attitudes and behavior are far more loosely coupled than the standard model suggests, and in many cases behavior changes first, with attitudes shifting afterward to justify it, not the other way round.

His central example: a 1990s US "five-a-day" campaign to encourage eating five portions of fruit and vegetables daily quadrupled the share of the population who believed they should eat five a day (8% in 1991, to 35% by 1995) — a genuinely large attitude shift. Measured actual eating behavior over the same period did not move at all (see US Five-a-Day Attitude Campaign vs No Behavior Change).

Reinforcing the same point from the opposite direction: John Darley and Daniel Batson's classic study found a trainee priest's stated motivation for entering the priesthood (personal salvation vs. helping others) had no bearing on whether he stopped to help a stranger in apparent distress — only how rushed he was mattered (see Darley and Batson Good Samaritan Priest Study). Attitude told you almost nothing; the situational variable told you everything.

The practical implication Barden draws is to intervene directly on behavior — via Choice Architecture (Salience & Placement), defaults (see Default Effect (Opt-Out vs Opt-In)), or framing (see Framing Effect) — rather than trying to first win an attitude change that may not translate into action at all.

Rory Sutherland argues the causal arrow runs backwards more often than assumed (Episode 179): behavior changes first, and attitude follows to resolve the resulting cognitive dissonance, not the other way round. Few Tesla buyers, he argues, bought their car principally for environmental reasons — many bought it because they liked the technology and design, then developed stronger environmental convictions afterward to justify the purchase to themselves. He reports the identical pattern in his own life: switching to a fully remote job that involved more time in specialty coffee shops changed his coffee attitudes, not the reverse. A failed "one bin is rubbish" recycling campaign taught him the same lesson operationally: households given two separate bins recycled far more reliably than households with one, regardless of stated environmental commitment — behavior is often a product of environment and interface, not intention (see McDonald's Touchscreen Two-Burger-Order Case for a related interface-changes-behavior example, and Pension Contribution Interface Friction Case for a case where interface friction suppresses a behavior most people would say they intend to do).

Richard Chataway extends the same gap to market research generally: what people say in research routinely fails to predict what they actually do. A politically-neutral newspaper that tested well in research shut down after three months (see Trinity Mirror New Day Newspaper Launch Failure); a rebrand consumers said they'd embrace instead cost the brand 20% of sales (see Tropicana Rebrand Failure); and a 2010 UK sex survey produced logically impossible self-reported averages, showing systematic over- and under-claiming baked into stated data (see NatSAL Sexual Partner Count Survey Discrepancy).

Re-cited in the 2024 year-end recap with new supporting evidence (Episode 218). Sutherland's McDonald's touchscreen and two-bin recycling examples are re-told alongside a new Starbucks example: the mobile-ordering app now drives roughly 50% of US Starbucks sales, has 25 million weekly users, and coincided with an estimated 11% year-on-year sales growth (see Starbucks App Channel-Loyalty Case). Sutherland also names the underlying phenomenon "intentionality bias," citing Evelyn Rosset's 2008 finding that 60-70% of people judge even unambiguously accidental actions (like losing one's keys) as intentional — evidence that a customer's own stated reason for a purchase may be a post-hoc reconstruction rather than the real cause (see Rosset 2008 Intentionality Bias Study). Sutherland further notes intentionality bias is more pronounced in Western cultures, which more often explain behavior by reference to a person's character rather than their situation — the same asymmetry behind the Fundamental Attribution Error.

Discussed in

  • Episode 20 — 20- Debunking a marketing myth
  • Episode 26 — 26- Why do 80- of product launches fail
  • Episode 179 — 179-it-s-how-mcdonald-s-make-men-binge-rory-sutherland (behavior-precedes-attitude examples)
  • Episode 218 — 218-the-best-of-nudge-in-2024 (Starbucks app case; Rosset 2008 intentionality-bias study)

Related