To understand the human capacity for psychological altruism, one requires a proper understanding of how people actually think and feel. This paper addresses the possible relevance of recent findings in experimental economics and neuroeconomics to the philosophical controversy over altruism and egoism. After briefly sketching and contextualizing the controversy, we survey and discuss the results of various studies on behaviourally altruistic helping and punishing behaviour, which provide stimulating clues for the debate over psychological altruism. On closer analysis, these studies prove less relevant than originally expected because the data obtained admit competing interpretations – such as people seeking fairness versus people seeking revenge. However, this mitigated conclusion does not preclude the possibility of more fruitful research in the area in the future. Throughout our analysis, we provide hints for the direction of future research on the question.

People sometimes think in terms of ‘we’ referring to a group they belong to. When making decisions, they frame the decision problem as: ‘What should we do?’ instead of ‘What should I do?’. We study one particular approach to such ‘we-reasoning’, economist Michael Bacharach's theory of ‘team reasoning’, and relate it to philosopher Raimo Tuomela's distinction between ‘I-mode’ reasoning and ‘we-mode’ reasoning. We argue that these theories complement each other: Tuomela's philosophical theory provides a conceptual framework augmenting Bacharach's theory, and Bacharach's mathematical results support Tuomela's view on the irreducibility of the we-mode to the I-mode. We-mode reasoning can explain some kinds of human cooperative behaviour left unexplained by standard game theory. Standard game theory is not well-equipped to deal with we-mode reasoning but it can be extended by the methods developed by Bacharach. However, we argue that both standard game theory and Bacharach's theory require more attention to the information-sharing stages that precede actual decision making, and we describe a stage-based model of we-reasoning.

This essay criticizes the proposal recently defended by a number of prominent economists that welfare economics be redirected away from the satisfaction of people's preferences and toward making people happy instead. Although information about happiness may sometimes be of use, the notion of happiness is sufficiently ambiguous and the objections to identifying welfare with happiness are sufficiently serious that welfare economists are better off using preference satisfaction as a measure of welfare. The essay also examines and criticizes the position associated with Daniel Kahneman and a number of co-authors that takes welfare to be ‘objective happiness’ – that is, the sum of momentary pleasures.

In this paper I study intentions of the form ‘I intend that we . . .’, that is, intentions with a we-content, and their role in interpersonal coordination. I focus on the notion of epistemic support for such intentions. Using tools from epistemic game theory and epistemic logic, I cast doubt on whether such support guarantees the other agents' conditional mediation in the achievement of such intentions, something that appears important if intentions with a we-content are to count as genuine intentions. I then formulate a stronger version of epistemic support, one that does indeed ensure the required mediation, but I then argue that it rests on excessively strong informational conditions. In view of this I provide an alternative set of conditions that are jointly sufficient for coordination in games, and I argue that these conditions constitute a plausible alternative to the proposed notion of epistemic support.