Adaptive lag is an important concept in memetics, since the lifecycles of cultural creatures is very rapid - and so cultural adaptations happen much more rapidly than genetic change in the human gene pool does. That means the human genome lags behind the cultural memome, as though being dragged along behind it on a very long, elastic leash.
Experts on cultural evolution Laland and Brown apparently disagree with the idea that humans suffer much from "adaptive lag". In an interesting article titled: "Niche Construction, Human Behavior, and the Adaptive-Lag Hypothesis".
They make three points:
- Humans Construct Their World to Suit Themselves
- Humans Frequently Buffer Adaptive Lag Through Cultural Niche Construction
- When Humans Are Unable to Buffer Adaptive Lag Fully Through Further Cultural Niche Construction, Natural Selection on Genes Ensues
However, adaptive lag is still an important concept. Drop an adult hunter-gatherer in NYC and you will see the effects of adaptive lag in action. Perhaps we should say "adaptive lag in DNA-genes" - to emphasise the intended perspective.
Also, look at the humans in Japan. Japan is thriving culturally - but it is the memes that are thriving the most. DNA genes are not doing so well by comparison. Again, the DNA-genes exhibit an "adaptive lag".