3 hours ago, chromedome said:I believe (but have not bothered to verify) that the use of it to describe a person, or said individual's frame of mind, is derived from the culinary adjective.
Without wishing to get too off-topic, it's the opposite. 'Stodgy' originally meant 'muddy' and the culinary usage followed a short time later. Its use to describe a person's thinking came from the earlier meaning.