Give me your imagination for a few minutes and try to see yourself as two different creatures experiencing similar dangerous events. First, I want you to imagine yourself as a dragonfly foraging over a small swampy area. [Wow, there are so many mosquitoes.] You slip and slide in the air, foraging to your gain. Then, out of the corner of your compound eyes you see, with your motion detector retinal cells, an image of something large ap proaching very rapidly. You drop quickly to the right as a frog's tongue flicks past. [Whew!]you think, [That was close.] You then dive on another mosqui to. The event is over.
Now let's imagine a similar situation; this time with you as a human. A car, traveling well over the posted speed limit, roars past your position. You, a rookie police officer, slap on your siren and lights, and take off after the speeder. The offending car slows and pulls off to the side of the road. Before getting out of your police car, you radio in the speeding car's license plate. Then you step out of your car and cautiously approach. Just as you get up to the car, the driver opens the door, points a pistol, and fires twice. One bullet strikes you on your left side and knocks you to the ground, but your body armor has deflected the bullet away. The second shot misses. The felon speeds away. Afterward, you are not able to return to work because of the trauma. And, for years your waking moments, your dreams, and your imag inations are filled with horrors of that night.
Is it a uniquely human capacity to experience psychological trauma? Is it our ability to foresee that we, or another of our species, shall ultimately die, which predisposes us to experience posttraumatic stress disorder (PTSD)? Does an organism require a sense of future to experience [fear and trembling and the sickness unto death] as the great existentialist philosopher, Kierkegaard (1954) suggested. We simply don't know. Animal behaviorists, including Jane Goodall, have described cases of animal ]grief' that resemble the horrors of our own experience (de Wall, 2001). But, can animals experience PTSD? There is no question that animals, other than human beings, experience severe stress-related problems (Sapolsky, 1994). Stress responses in animals usually occur following prolonged periods of unpredictable noxious stimulation (e.g., Seligman, 1975).