Neuroticism is not the only personality dimension that can cause psychological vulnerabilities. Sauer-Zavala says high levels of conscientiousness can tip into perfectionism, something I relate to. The interventions Sauer-Zavala suggests for this make my skin crawl: "Figure out what 80% of your best job is, do that and stop there and see what happens," she says. "Or send an email with a typo, or leave work at five o'clock every day this week. It's usually the most anti-climactic thing." 

I compulsively check and re-check any bit of work or correspondence before I send it off. After Sauer-Zavala's comments, I try to stop myself before doing a final-final-final check on a bit of corporate work, and just send it. I can't help opening it once more afterwards and spot what I see as a glaring error, the close repetition of a certain word. I feel a pang – see! But of course she's right, it doesn't matter in the slightest, and I quickly forget about it.

By the end of my six weeks of experimentation, I didn't feel radically different, but I did feel pretty good. The moment had come to re-take the test. Early on, I sensed that I might evince some changes. In answer to a question about whether I was "outgoing and sociable", I felt sure I would have previously disagreed. This time, I had six weeks of unignorable data in front of me. Objectively, I had socialised, often with strangers, and had a not bad time. So maybe I was sociable after all. The researchers were right that acting in a certain way can change your perception of yourself.

More like this:

• Our 2,500-year-old mania for personality types

• How birth order shapes your personality

• How your personality changes as you age

Answering questions like this helped push me from the 30th percentile on extraversion to the 50th. On agreeableness, I also hugely improved, shifting from the 50th to the 70th percentile. It seemed that thinking nice things about people had indeed made me more positively disposed to humanity. On neuroticism, I showed a marked improvement, dropping from the 83rd percentile to 50th. I stayed roughly the same on conscientiousness and openness.