Psychological Adaptations (PA) appear to be a group of different skills, comparable to a bundle of different plants pulled by the roots and then tied together by runners.
1) Different plants in the bundle have different features such as leaves or petals and different functions. They have different colors, sizes, and aromas. They demand different nutrients. Likewise for our PAs.
2) They are not always compatible. Lateral inhibition (reciprocal inhibition) occurs at nearly every level to produce coordinated behavior of the intact creature. Active sensory neurons inhibit those that are less active. Increased tension in one muscle decreases tension in the opposing one. PAs associated with eating may inhibit PAs associated with fear or anger. Likewise for PAs tied to mating, escape, or anger. PAs associated with a particular talent may inhibit PAs associated with escape, avoidance, shame, or guilt.
3) Different expressions of any one PA can exist in a group of people just as the plants can have differing colors and sizes, and be of different ages. PAs can be of differing strengths & weaknesses in different people. There will be talented nannys and talented engineers and talented hunters and perhaps a few gifted people who can do all three.
4) PAs are not saggital pieces but vertically running systems. Thus, it is possible to elicit the same or highly similar behaviors at different levels in the bundle. Removing a segment may disrupt one PA but similar PAs may take over some of the functions of the missing unit. The creature solves old problems in a different manner.(2)
5) The PAs seem functionally parallel. Thus, you can elicit eating, drinking, mating, and aggression from adjacent electrode placements in some parts of the brain. They are elicited by more diverse points as you move to limbic or cortical levels.
6) Cortical, limbic, hypothalamic, reticular, spinal, organ, muscle, and sensory components vary across PAs. Some psychological phenomena appear to be saggital events rather than vertical. Mania, anxiety, or depression affect several, but not all PAs at the same time or to the same degree. Anxiety is often content specific. It's possible for Janie to be apathetic or furious towards her parents and about keeping her room neat but she chatters, plans, and manipulates when dealing with friends.
7) Some PAs operate independently of conscious representation. In some senses, you talk to your spleen and it answers. But, you don't know what you said or what you heard. There are no cortical representations of either the direction or the feedback. Still, your spleen is perfectly happy and usually does its job without your conscious intervention. It's difficult to imagine a spleen with bipolar disorder!
8) The structure of many PAs is not immediately clear. We have limited feedback systems that allow us to check on our PAs; we are not aware of how "content specific" they are. A similar phenomenon occurs with "paying attention." If you don't have the mechanisms to monitor "attention," then you can't report on it. You also need some baseline for comparison such as your ability to attend at other times of your life, to attend as a function of the topic, or comments from teachers and friends. Preadolescent, ADHD children typically underestimate their difficulties with attention. They could be minimizing the problem or they may in fact not be aware of their difficulty and its severity.
9) Most PAs are older than language. PAs similar to the human examples operate in other species that have no oral expressive language. Adaptations that exist independently of language include succorance, sympathy, empathy, reciprocal altruism, grieving, awe, and sanctions for selfishness, unfair aggression, mate swapping, lying or stealing.
10) Integration of past experiences occurs with different PAs and to different degrees. Due to "learning," signals that once elicited one PA can elicit an opposing PA.
11) PAs appear to be "nested." That is, heart regulation appears to have adaptive significance; species with heart regulation have a survival advantage. However, heart regulation can be influenced by other PAs associated with mating, eating, relaxation, and a wide range of previously neutral stimuli.
12) Clinical syndromes, thus, involve symptoms across a wide range of levels and may involve a number of related PAs. For example, anxiety can be associated with changes in heart rate, blood pressure, sweat production, stomach acidity, sleep patterns, breathing, cognitive content, and cognitive rigidity.
13) Some clinical problems may be due to impaired PAs. For example, Cantwell suggested that ADHD is earmarked by a lack of interpersonal sensitivity. There's less ability to empathize and to adjust personal behavior accordingly.
14) There are likely distributions of some PAs according to sex. Child rearing skills, and mate selection are possibilities. One scientist has found that men, but not women, have difficulty recognizing distress in photographs of women but not of men! Women can accurately label feelings in photographs of either sex.
1) Kevin Kelly (1994, Out of Control: The New Biology of Machines, Social Systems, and the Economic World, Reading, MA: Addison Wesley) describes experiments in which identical seed mixtures are planted each year in a field. The pattern of growth is never the same. I likewise mow my back field twice each spring and watch differing waves of plant types each year. Jonathan Schull (Einstein Institute, August 1996) once compared these effects to passing clouds if you were to watch the field from above and with a compressed time line. Similar patterns could also be seen if we did the same while watching the dispersal and modification of wild creatures or of ourselves. Thus, the point is often made that if evolutionary dice were rolled again, we likely would not result.
2) Generally, people who studied the brain by electrical stimulation supported a "specificity" model of neural function. People who cut out sections supported a "mass action" principle. Both are true.