Reed and Bennett talk about juror secrets here and here. Anne presented the problem - the jurors have secrets and we need to know them. Mark presented the answer - we must first reveal our secret before the jurors will reveal theirs. Mark was describing reciprocity. In other words, a person responds to what is given to them. Sad for sad. Fear for fear. Slow for slow. Secret for secret.
Reciprocity is a powerful tool for the criminal defense lawyer which helps us connect with other human beings. The power in revealing ourselves to another is the affect it has upon the listener. During jury selection, when the trial lawyer reveals herself to a potential juror, she is connecting with another human being while developing rapport and trust. When a juror trusts us they will reveal things to us, even in a crowded room where other people are listening.
When there is no trust between lawyer and juror there is a psychological barrier separating the two. It is us versus them. We break down the barrier when we expose our own vulnerability. Once the juror realizes were are really one of them, they are better equipped to reveal their own vulnerability, i.e., their secrets.