A psychologist by the name of Martin Seligman ran a two part social experiment to test learned helplessness some years ago. In it, he takes three dogs and puts them through similar situations, changing slightly a couple of variables to demonstrate his theory. In part 1, Dog A is tied up in a harness and then released. Dog B is tied up in the harness, and then shocked with painful, electric current, which he can end by pressing a button. Dog C is tied up in a harness and shocked with painful, electric current but given no way out from it. Already Dog C begins to show symptoms of depression.
In the second part, all three dogs were placed separately into a box that was divided into two parts with a small partition. The first part of the box was injected with current similar to that which was used in part 1 of the experiment. To escape the current, the dog would just have to jump over the the partition into the second part of the box. Dog A, who had not been shocked in Part 1 of the experiment, finds his way out. Dog B, remembering when it feels this kind of pain has a means of escape, looks for his way out and finds it. Dog C, having full opportunity to jump over as the earlier two did, does not. When it is shocked, it remembers the pain that it felt from Part 1 of the experiment and that there was no way out from it. So rather than jumping over the partition like the first two, he just lays down and whimpers until someone comes and helps him -- completely helpless because of how he was treated. We learn in a similar way and, unfortunately, when we are not mindful of our words, we teach in a similar way too. They really can make someone feel helpless.