Briony D. Pulford

Learn More
The influences of optimism and pessimism on ambiguity aversion were investigated in two tasks that manipulated the presence or absence of a potentially competitive experimenter. A total of 112 participants chose which option--ambiguous or known-risk--they preferred in the two slightly differing Ellsberg urns tasks. Optimism was measured using the Extended(More)
In individual choices between alternatives x and y, the availability of a third alternative z, judged inferior to x but not to y, tends to increase preferences for x. Two experiments investigated corresponding strategic asymmetric dominance effects in games. In Experiment 1, 72 players chose strategies in six symmetric 3 · 3 games, each having one strategy(More)
Overconfidence is said to occur when a person's confidence in a series of predictions exceeds the level of accuracy achieved. In this experiment, questionnaire items requiring predictions of personal life-events were selected according to their objective base rates of occurrence and their outcome positivity /negativity for participants in a pilot study. The(More)
Decision theory and game theory rest on a fundamental assumption that players seek to maximize their individual utilities, but in some interactive decisions it seems intuitively reasonable to aim to maximize the utility of the group of players as a whole. Such team reasoning requires collective preferences and a distinctive mode of reasoning from(More)
The problem of ambiguity in games is discussed, and a class of ambiguous games is identified. A total of 195 participants played strategic-form games of various sizes with unidentified co-players. In each case, they first chose between a known-risk game involving a co-player indifferent between strategies and an equivalent ambiguous game involving one of(More)
When attempting to draw a ball of a specified color either from an urn containing 50 red balls and 50 black balls or from an urn containing an unknown ratio of 100 red and black balls, a majority of decision makers prefer the known-risk urn, and this ambiguity aversion effect violates expected utility theory. In an experimental investigation of the effect(More)
The influence of Perfectionism, Self-esteem and Self-efficacy on Self-handicapping in studying was investigated in relation to individualism and collectivism in students in the United Kingdom and Lebanon. One hundred and twenty eight participants (64 UK and 64 from Lebanon) completed the Individualism and Collectivism Scale; the Multidimensional(More)
Hypothetical trolley problems are widely used to elicit moral intuitions, which are employed in the development of moral theory and the psychological study of moral judgments. The scenarios used are outlandish, and some philosophers and psychologists have questioned whether the judgments made in such unrealistic and unfamiliar scenarios are a reliable basis(More)
The similarity discrimination effect occurs when a single gene or gene cluster causes its carriers to display both a variable phenotypic trait and a behavioural predisposition to cooperate preferentially with recognisably similar carriers. We distinguish this from the greenbeard effect, in which cooperation evolves through fixed phenotypic tags and(More)
In a market entry game, the number of entrants usually approaches game-theoretic equilibrium quickly, but in real-world markets business start-ups typically exceed market capacity, resulting in chronically high failure rates and suboptimal industry profits. Excessive entry has been attributed to overconfidence arising when expected payoffs depend partly on(More)