Yes, password manager
This jibes with other studies that the more you actually know about security the more you're likely to use a password manager and generate huge random passwords for each site. See https://www.schneier.com/blog/archives/2014/09/security_of_pas.html , http://www.theguardian.com/technology/2015/jul/27/security-experts-keep-safe-online-password-manager-seven-things , etc. Even a text file qualifies as long as you're using really random long passwords.
But there's still a substantial group of Dunning-Kruger types who know just enough about security to be dangerous and think they're smarter than that and come up with bizarre password or phrase generation schemes. I know one of them. He has to use password reset quite frequently because his algorithm is so clevar he can't reproduce the passwords reliably. Or maybe that's a feature! Also fairly sure if I got one of his plaintext passwords I could figure out the basic scheme... Except for the too clever by half bit.