Here is a new post at EconLog in which Bryan Caplan discusses how signalling contributes to the status quo bias.
The lesson: In the real world, signaling naturally tends to ossify behavior - to lock in whatever the status quo happens to be. If you're an optimist, you can protest, "It's only a tendency." But even an optimist should admit that this tendency leads to atypically slow and unreliable progress.
AFAIK, it is well established that IQ positively correlates with many performance metrics for levels of IQ around and below the average, while the correlation for above average IQ is more dubious.
Here is a new post at EconLog in which Bryan Caplan discusses how signalling contributes to the status quo bias.