Mean IQ world-wide (and also in America) is 100. Software engineers here in San Francisco are nowhere close to average intelligence across the US. Data shows differences across professions for IQ, and software engineering lands firmly on the 2 stddev (130 IQ) mark. Remember, populations aren't distributed evenly, and smarter people than average tend to end up in SF Bay. It's difficult to be well-calibrated if you haven't spend enough time outside the bubble here.