There’s a personal development speaker in Romania (focused on financial investments) who really pushes determining your personal profile, and based on that profile, you could make a realistic investment strategy.
The issue? Most people don’t start with investing a fortune. As far as I see it, it’s better to just start investing and see how you respond to things.
Are you good with handling rent for a property you invested in?
Do dividends for the company you bought shares at come with a good ratio?
Just splitting 20-30-50 between three main assets is not, in my opinion, the best choice, and just letting life (and mistakes, of course) do their course is the way to go.
My main issue with the principle „from personality we’ll determine an investor profile” is that there are a lot of unknowns – how will you handle a real estate? Do you like the stress of the Stock Exchange? Would you prefer investing in small businesses?