Rationality and Social acceptance

I've just listened an interview of Bob Lutz, who wrote "Car Guys vs. Bean Counters: The Battle for the Soul of American Business" (haven't got that book, though). One point caught my attention. Lutz said something like "Customers always tell you the rational, socially acceptable reasons when doing customer research with interviews". In the context of car manufacturing, this means that most wanted features in cars are reliability and safety. But when the buying decision is made, it is the irrational reasons that matter.

So you could say that customers doesn't know what they want, and most of customer research by interviews or requirement gathering might be waste. Customers and end users just say what they think is the norm in the domain, they don't think what they really need. They only give the rational and socially acceptable requirements. So what is needed is deeper research on what users really need, interviews or planning meetings aren't enough, and might actually be harmful.