Cultural adaptation is path-dependent and condemned to local optima
Evidence
Real-world environments probably result in complex fitness topographies containing a variety of peaks, valleys, chasms, and plateaus. Consequently, slight variations in initial conditions (the starting position on the fitness landscape) can drive two quite similar populations toward increasingly divergent adaptive “peaks” or solutions (see Boyd and Richerson 1992a for discussion and further references). And, because many adaptive behavioral practices involve the accumulation and integration of many different traits, and the addition of each new behavioral component alters the conditions for subsequent additions, most changes or novel traits are likely to produce maladaptive effects once a local optimum is reached. Jumping from one optimum to another becomes difficult, because it requires simultaneously altering a number of traits in just the right way so as to land on a superior peak and avoid dropping into fitness valleys. Normally, most adaptive cultural practices require a gradual accumulation of innovations, and consequently “peak-shifting” is rare even for simple, nonintegrative adaptive traits. — Joe Henrich and Robert Boyd, The Evolution of Conformist…, 113
Categorization
- XREF: This is the foundational fitness-landscape argument Boyd and Richerson developed that Henrich later popularized — connects directly to the reading purpose on the original technical model. — connects to: Survival rests on inherited cultural adaptations no individual could improvise alone — Joseph Henrich, The Secret of Our Success: How Culture…, 117; Cultural accumulation locks groups into local optima because traits are integrated; Cultural evolution can lock groups into maladaptive equilibria, not just prosocial ones (+1 more)
- QUESTION: The claim that peak-shifting is ‘rare even for simple, nonintegrative adaptive traits’ deserves scrutiny — worth chasing what empirical examples Boyd and Richerson marshalled.