Conditioned by that training, we have become vulnerable to manipulation. We would live a difficult life if we had to be always on our guard, mistrustful of others, concerned that we might become the dupe of someone trying to take advantage of us. In a perfect world we would implicitly trust others, confident that the people we encounter are going to be honest and trustworthy. But we do not live in a perfect world, and so we have to exercise a standard of vigilance to repel the deceptive efforts of our adversaries.