Nice. Just ordered it for my University Library, hopefully that might make it more likely that someone else reads it too.

I'm curious about your musings on the connection between masturbation and risk-taking. Would it be mediated by testosterone levels?

I've heard several people mention the idea that frequent masturbation would lower testosterone levels. But after a very brief search, I found claims that no studies supporting such a relationship exists, and a study (admittedly with few subjects) which failed to find any effects from sexual activity on blood plasma testosterone levels. Know any results to the contrary?

Very useful info.

I'd love to come, but I live too far away for it to be practical for me to go to Stockholm just for a LW meetup. Would anyone be interested in a Malmö/Lund meet-up?

How to structure work-outs. Should I lift as much weight as possible or do more repetitions at lower weights?

High weight, no doubt. Aim for ~8 Reps. Focus on exercises that use multiple muscle groups. ie. Squats, bench press, lat pull down.

How should I trade off frequency of gym visits against length of those visits?

Low frequency. Give yourself time to recover. Don't make the length too high either. The sets you do should be intense. You should be as exhausted as possible after you finish them.

What supplements should I take?

'Roids, if you are optimizing for physique (but probably not if you are optimizing for, well, life in general). More sensibly supplement protein. Play with some creatine if you are enthusiastic, particularly if you are into the appearance boost.

Nice post. It seems like a good summary of important results from happiness science, with interesting ideas about how to increase one's social skills added. Some comments:

So which personality traits tend to correlate most with happiness? Extroversion is >among the best predictors of happiness,22 as are conscientiousness, >agreeableness, self-esteem, and optimism.23

I'm surprised that you don't mention the trait neuroticism, which in many studies has the strongest correlation with happiness. (see eg) In general, neuroticism and extraversion are far better predicators of happiness than conscientiousness and agreeableness (even if the latter traits have some effect).

One benefit of religion may be that it gives people a sense of meaning and >purpose

Interestingly, religion doesn't correlate with happiness in more athestic (compared to US) european countries like Sweden. One way to explain this is that much of the effect is socially mediated and that less of the effect is meditated by finding meaning in life.

Many people report that constantly checking to see if they are happy actually >decreases their happiness

Do you know of any studies showing that checking if you are happy reduces happiness? As far as I know very few empirical studies have been done and this idea is mostly based on philosophical speculation by people like J.S. Mill and Sigdwick ("The paradox of hedonism").

Some support for hypothesis 4 (assuming a correlation between status and age):

Not only do studies show that fluid intelligence decreases with age but the psychological trait Openness to experience also declines with age. Openness is related to characteristics like curiosity, independence of mind and broad interests, which should facilitate the possibility of having an "intelligent conversation".