Parental investment

A model of the optimal amount of parental investment for males of low and high fitness. The male of high fitness pays a lower mating cost (M) than the male of low fitness and therefore maximizes fitness returns (the slope of a tangent line between M and the returns on parental investment by investing less in offspring (P). assumption is that mating effort and provisioning of material investments are significantly exclusive activities. In some instances this assumption should not hold....

Equivalence Classes

Laboratory studies of equivalence class formation suggest that many animal species can be taught to place dissimilar stimuli into the same functional class. For example, Schusterman and Kastak (1993, 1998) taught a California sea lion, Rio, to group seemingly arbitrary stimuli into equivalence classes in the following manner. First, Rio was presented with three visual stimuli together, so that she learned to associate, for example, Al, A2, and A3 even though they shared no physical features....

Chunking in Human and Animal Memory

To survive and reproduce successfully, nonhuman primates must be able to predict the behavior of others. Predicting other animals' behavior demands, in turn, that individuals memorize information about all of the d adic and triadic relations in their group. And, as already noted, memory loads will be enormous in species with large social groups because increases in group size lead to an explosive increase in the number of dyads and triads. Faced with the problem of remembering long strings of...

Odors Pheromones or Vasanas

Although the full extent of the impact of odors on psychological state is still largely unexplored scientifically, there is evidence that odors do affect human psychological states and behavior, presumably acting through the main olfactor) pathwa . The hedonic qualities of odors in everyday life are commonly recognized and inescapable, and scientific evidence is growing. For example, people living within smelling distance of a pig farm experience depressed mood significantly more often than...

Gerd Gigerenzer

A cartoon shows an early Homo sapiens standing in front of a cave. He is calculating the trajectory of a lion's jump and the magnitude of the impulse the lion will have in order to decide what to do. The last picture shows a sated, happy lion. The cartoon makes us smile because its message conflicts with our ideal of rational decision making, which demands that we go through all the available information, deduce all the possible consequences, and compute the optimal decision. Good decision...

The Building Blocks of the Adaptive Toolbox

The building blocks of the heuristics in the adaptive toolbox include rules for search, stopping search, and decision making. By recom-bining different building blocks, the adaptive toolbox can create new heuristics. For instance, in a situation in which Take The Best cannot be used because an individual does not have the knowledge to order the cues according to their validity, a less demanding search rule can be used instead that searches for cues in random order or simply tries the cue first...

Vasana A New Class of Social Chemosignals

Clearly, we need a term describing those social chemosignals that are neither odors nor pheromones. That is, chemosignals that are not consciously detectable as odors (at least verbally), do affect psychological state, and yet do not trigger a unique set of behavioral, neural, or endocrine responses that are necessary to fulfill the definition of a pheromone. Such social chemosignals are remarkably similar to the medieval Sanskrit term vasanas. Vasana, the singular noun, is derived from the...

Sources of Human Social Chemosignals

The steroids we tested are strong candidates for being functional social chemosignals among humans. Both chemicals are naturally occurring steroids in humans and were first measured in human blood over two decades ago, using standard radioimmunassay techniques. For example, in peripheral plasma of men, androstadienone has been measured at 0.1-1.0 jog liter unconjugated (Brooksbank, Cunningham, & Wilson, 1969 Brooksbank, Wilson, & MacSweeney, 1972 Fukushima, Akane, Matsubara, & Shiono,...

Psychological Effects of Androstadienone and Estratetraenol

Two steroids A4,16-androstadien-3-one androstadienone and 1,3,5, 10 ,16-estratetraen-3-ol estratetraenol are claimed to be human behavioral pheromones, and are used as active ingredients in fragrances and commercial products. The steroids are claimed to have releaser effects, stimulating specific social cognitions and motivations increased self-confidence, well-being, friendliness and sociability Kodis, Moran, amp Houy, 1998 . These behavioral pheromone claims were supported by evidence that...

Risk Acceptance and Discounting of the Future

The rate at which one discounts the future is the rate at which the subjective value of future consumption diminishes relative to the alternative of present consumption or, if you like, the interest rate required to motivate foregoing consumption . If A discounts the future more steeply than B, then A will value a given present reward relative to expected future rewards more highly than B and will be less tolerant of delay of gratification. Psychologists, economists, and criminologists have...