Modulação circunstancial do desconto temporal: impacto de estímulos sobre a tomada de decisão nas esferas de negociação entre presente e futuro

Abstract

Humans and other organisms generally discount the future, preferring immediate over delayed rewards. This general preference is understandable, largely because delaying consumption increases the risk of losing the benefit. Moreover, the intertemporal impatience can be adaptive. Earlier reproduction produces an average increase in the rate of reproductive success than later reproduction. However, although it is a general tendency, the future discounting may vary temporarily due to contextual stimuli, especially cues of sexual opportunities. The objective of this study was to investigate situational sources of variability in time preference. To this end, four studies were conducted to evaluate the effects of cues of reciprocity, conditioned arbitrary contextual stimuli, and quality of limiting resources on the rate of future discounting, using: (1) images of the opposite sex expressing happiness and disgust, (2) videos of people engaged in friendly and non-friendly interviews, (3) colors of the experimental environment associated with images of the opposite sex, and (4) pictures of attractive and unattractive food. The effects of these stimuli were measured using a task that is often used to evaluate future discounting, formed by two sets of monetary choices completed by participants before and after the stimulation. Each monetary choice has two options: a monetary value for tomorrow (x) or more (x + y) in a specified future (z days). Additionally, we investigated individual sources of variation in time preference. For this purpose, a correlational and transversal study was conducted using structured questionnaires to investigate possible predictors of future discounting. The aim was to examine the relationship between future discounting rates and individual differences such as gender, age, risk propensity, and socioeconomic indexes. The results show that the future discounting rates can be increased in the presence of long-wavelength color associated with states of arousal as opposed to short-wavelength color, and decreased by exposure to high-calorie food stimuli compared to low-calorie food stimuli. Moreover, the future discounting shows a negative correlation with socioeconomic status, and that the latter can predict high rates of temporal discounting. It is concluded that the future discounting may vary depending on the activation of arousal state, basic motivational systems, and in response to scarcity of material resources. Jointly, the results are consistent with the interpretation that immediate choices are related in evolutionary terms to fitness maximization in certain environments, and that the time preference is a multidimensional process, possibly comprising distinct domain-specific mechanisms.

Propensão ao risco diante de contextos de imprevisibilidade: uma análise do comportamento humano pela abordagem evolucionista

“…Uma hipótese para a falta de diferenciação significativa das médias de propensão ao risco pode estar relacionada ao tipo de mensuração e análise realizada. Enquanto em outros trabalhos (Wilson & Daly, 2004;Cosentino, 2012;Ferreira, 2013) essa medida é feita a partir de medidas repetidas: linha de base, apresentação de estímulo e resposta após estímulo, neste trabalho comparamos médias de participantes de diferentes grupos. Sugerimos que, para este tipo de estudo, é mais adequado testar o mesmo sujeito, comprando com linha de base, visto que cada participante pode apresentar uma média de propensão ao risco mais ou menos alta, dependendo de fatores tais como percepção de risco, habilidade na tarefa, entre outros (Douglas & Wildavsky, 1982;Baron, 1994).…”

“…Mesmo diante de fragilidades metodológicas, as quais precisam ser revistas em trabalhos futuros, os participantes mostraram-se sensíveis aos estímulos, assim como em outras pesquisas (Wilson & Daly, 2004;Cosentino, 2012;Ferreira, 2013 qual os prepara corporalmente para ações de esquiva ou fuga diante de situações perigosas.…”

“…De acordo com essa teoria, decisões de ação ou decisões de como investir esforços (energia, tempo e recursos) são tomadas frente a dilemas evolutivos com os quais os indivíduos deparam ao longo da vida (Roff, 1992;Geary, 2002;. Esses dilemas referem-se a dois domínios de alocação de investimento, o somático e o reprodutivo (Williams, 1966;Voland, 1998;Geary, 2002 (Wilson & Daly, 2004;Cosentino, 2012;Ferreira, 2013).…”

“…(b) Influência da manipulação contextual de imprevisibilidade nas médias de propensão ao risco: Trabalhos (Wilson & Daly, 2004;Cosentino, 2012;Ferreira, 2013) demonstram que a manipulação contextual por meio de imagens auxilia no aumento de médias de escolha por opções mais arriscadas. (Trivers, 1972).…”