A Cognitive Password is a password used as a response to a question that pertains specifically to the user. Secret questions/answers used to reset passwords are cognitive passwords. (eg. What is your favorite food?) Social Media can be used to obtain information about a user and allow cognitive passwords to be easily guessed.
A cognitive password is a form of knowledge-based authentication that requires a user to answer a question, presumably something they intrinsically know, to verify their identity. Cognitive password systems have been researched for many years and are currently commonly used as a form of secondary access. They were developed to overcome the common memorability vs. strength problem that exists with the traditional password. Cognitive passwords, when compared to other password systems, can be measured through the usage of a memorability vs. guessability ratio.