It may be, in part, a simple
lack of testosterone:
The Germans decided to study this aspect of testosterone in more depth. Testosterone is linked to pride and status seeking, they reasoned. Proud people lie less often. So subjects should become more honest if you give them testosterone – for example by rubbing the contents of a sachet of Testogel into their skin, which would supply them with 50 mg testosterone.
The more testosterone there is circulating in a man's body, the more honest he's likely to be. Even when he knows that no one is likely to find out that he is lying, he's more likely to tell the truth than a man with less testosterone in his body. The researchers administered the testosterone to just under 50 male subjects. Twenty hours later they got the subjects to throw a dice and record their scores on a computer. The higher their score, the more money they earned.
A score of 6 earned nothing. The researchers didn't check whether the men were cheating.
A similar-sized control group were given a placebo, and had to go through the dice routine too.
The men that had been given testosterone had an average level of 7.78 nanograms per millilitre during the experiment. The level in the placebo-group men was 6.79 nanograms per millilitre. The men in the testosterone group won 3.33 euros per throw, the men in the placebo group won 4.18 euros per throw.
I wonder how little testosterone a particularly dishonest Gamma like Scalzi has. I'd be surprised if he's over 2 nanograms per millilitre. But this points to ways Gammas can raise their sociosexual rank, which is engaging in activities and diets that raise testosterone and avoiding those that lower it.