This paper provides a comprehensive review of the experimental philosophy of action, focusing on the various different accounts of the Knobe Effect.

A large portion of philosophy done in the Western analytic tradition attempts to provide conceptual analyses which are tested by examples that elicit intuitions. These intuitions are, in turn, used as evidence either for or against a given analysis. In recent years, there has been much discussion of the uses of intuitions from empirically minded philosophers and psychologists. The basic strategy is to discover empirically how “normal” folks think about certain topics in philosophy. This application of folk intuitions to philosophy (...) branches into roughly two basic approaches. The first is an attempt to show that in given domains, folk intuitions are not very reliable sources of evidence; hence, we have good reason to think that philosophers' intuitions are also not reliable sources of evidence in that domain. The second approach attempts to determine what folk concepts are. Once folk concepts are analyzed, they are then argued to be relevant to philosophical debates. My guiding question for this dissertation is the following one: Why should philosophers care about folk intuitions? One answer is that we should want some philosophical analyses to be grounded in everyday concepts. I argue that there are presently no adequate a priori arguments for the reliability of philosophical intuitions in some philosophically relevant areas. Whether intuitions are reliable enough to ground philosophical analyses is an empirical question. I review four domains where ordinary concepts have been argued to ground philosophical theorizing: (1) epistemology, (2) ethics, (3) free will, and (4) action theory. I argue that the available evidence suggests that we should be skeptical of intuitions in philosophy—but that skepticism does not entail radical skepticism. That is, the empirical studies reveal a wide variety of results which on the surface indicate that intuitions are not reliable (e.g., order effects or framing effects). However, I argue that these seeming instabilities are actually the results of stable differences in different groups of people. Hence, I argue that intuitions are stable in a surprising way—that different groups of people have stable intuitions. This intuition stability, while not the kind of monolithic stability many philosophers might desire, is argued to be sufficient to ground philosophical analyses in these domains. (shrink)

Nearly all success is due to some mix of ability and luck. But some successes we attribute to the agent’s ability, whereas others we attribute to luck. To better understand the criteria distinguishing credit from luck, we conducted a series of four studies on knowledge attributions. Knowledge is an achievement that involves reaching the truth. But many factors affecting the truth are beyond our control and reaching the truth is often partly due to luck. Which sorts of luck are compatible (...) with knowledge? We find that knowledge attributions are highly sensitive to lucky events that change the explanation for why a belief is true. By contrast, knowledge attributions are surprisingly insensitive to lucky events that threaten but ultimately fail to change the explanation for why a belief is true. These results shed light on our concept of knowledge, help explain apparent inconsistencies in prior work on knowledge attributions, and constitute progress toward a general understanding of the relation between success and luck. (shrink)

Recent empirical and conceptual research has shown that moral considerations have an influence on the way we use the adverb 'intentionally'. Here we propose our own account of these phenomena, according to which they arise from the fact that the adverb 'intentionally' has three different meanings that are differently selected by contextual factors, including normative expectations. We argue that our hypotheses can account for most available data and present some new results that support this. We end by discussing the implications (...) of our account for folk psychology. (shrink)

Intuitions about intentional action have turned out to be sensitive to normative factors: most people say that an indifferent agent brings about an effect of her action intentionally when it is harmful, but unintentionally when it is beneficial. Joshua Knobe explains this asymmetry, which is known as ‘the Knobe effect’, in terms of the moral valence of the effect, arguing that this explanation generalizes to other asymmetries concerning notions as diverse as deciding and being free. I present an alternative explanation (...) of the Knobe effect in terms of normative reasons. This explanation generalizes to other folk psychological notions such as deciding, but not to such notions as being free. I go on to argue, against Knobe, that offering a unified explanation of all the asymmetries he discusses is in fact undesirable. (shrink)

The ‘Knobe effect’ is the name given to the empirical finding that judgments about whether an action is intentional or not seems to depend on the moral valence of this action. To account for this phenomenon, Scaife and Webber have recently advanced the ‘Consideration Hypothesis’, according to which people’s ascriptions of intentionality are driven by whether they think the agent took the outcome in consideration when taking his decision. In this paper, I examine Scaife and Webber’s hypothesis and conclude that (...) it is supported neither by the existing literature nor by their own experiments, whose results I did not replicate, and that the ‘Consideration Hypothesis’ is not the best available account of the ‘Knobe Effect’. (shrink)

A majority of people regard the harmful side-effects of an agent’s behavior as much more intentional than an agent’s helpful side-effects. In this paper, I present evidence for a related asymmetry. When a side- effect action is an instance of harming, folk ascriptions are significantly impacted by the relative badness of either an agent’s main goal or her side- effect action, but not her attitude. Yet when a side- effect action is an instance of helping, folk ascriptions are sensitive to (...) an agent’s expressed attitude, but not to the relative goodness of her main goal or side- effect. It seems that the connection between harmful side-effects and intentionality is, for many, uniquely impervious to the expressed attitude of the agent in question. (shrink)

A number of researchers have begun to demonstrate that the widely discussed ?Knobe effect? (wherein participants are more likely to think that actions with bad side-effects are brought about intentionally than actions with good or neutral side-effects) can be found in theory of mind judgments that do not involve the concept of intentional action. In this article we report experimental results that show that attributions of knowledge can be influenced by the kinds of (non-epistemic) concerns that drive the Knobe effect. (...) Our findings suggest there is good reason to think that the epistemic version of the Knobe effect is a theoretically significant and robust effect, and that the goodness or badness of side-effects can often have greater influence on participant knowledge attributions than explicit information about objective probabilities. Thus, our work sheds light on important ways in which participant assessments of actions can affect the epistemic assessments participants make of agents? beliefs. (shrink)

It has often been suggested that people's ordinary understanding of morality involves a belief in objective moral truths and a rejection of moral relativism. The results of six studies call this claim into question. Participants did offer apparently objectivist moral intuitions when considering individuals from their own culture, but they offered increasingly relativist intuitions considering individuals from increasingly different cultures or ways of life. The authors hypothesize that people do not have a fixed commitment to moral objectivism but instead tend (...) to adopt different views depending on the degree to which they consider radically different perspectives on moral questions. (shrink)

Theory of mind, the capacity to understand and ascribe mental states, has traditionally been conceptualized as analogous to a scientific theory. However, recent work in philosophy and psychology has documented a "side-effect effect" suggesting that moral evaluations influence mental state ascriptions, and in particular whether a behavior is described as having been performed 'intentionally.' This evidence challenges the idea that theory of mind is analogous to scientific psychology in serving the function of predicting and explaining, rather than evaluating, behavior. In (...) three experiments, we demonstrate that moral evaluations do inform ascriptions of intentional action, but that this relationship arises because behavior that conforms to norms (moral or otherwise) is less informative about underlying mental states than is behavior that violates norms. This analysis preserves the traditional understanding of theory of mind as a tool for predicting and explaining behavior, but also suggests the importance of normative considerations in social cognition. (shrink)

Fiery Cushman and Alfred Mele recently proposed a ‘two-and-a-half rules’ theory of folk intentionality. They suggested that laypersons attribute intentionality employing: one rule based on desire, one based on belief, and another principle based on moral judgment, which may either reflect a folk concept (and so count as a third rule) or a bias (and so not count as a rule proper) and which they provisionally count as ‘half a rule’. In this article, I discuss some cases in which an (...) agent is judged as having neither belief nor desire to bring about an action, and yet laypersons find the agent’s action to be intentional. Many lay responses apparently follow a rule, but many other seem biased. The contribution of this study is two-fold: by addressing actions performed without desire or belief, it expands Mele and Cushman’s account; it also helps discriminate between a two-rules and a three-rules theory. As a conclusion, I argue in favor of a three-and-a-half concepts theory. (shrink)

Chandra Sripada's (2010) Deep Self Concordance Account aims to explain various asymmetries in people's judgments of intentional action. On this account, people distinguish between an agent's active and deep self; attitude attributions to the agent's deep self are then presumed to play a causal role in people's intentionality ascriptions. Two judgments are supposed to play a role in these attributions?a judgment that specifies the attitude at issue and one that indicates that the attitude is robust (Sripada & Konrath, 2011). In (...) this article, we show that the Deep Self Concordance Account, as it is currently articulated, is unacceptable. (shrink)

Joshua Knobe (2003a) has discovered that the perceived goodness or badness of side effects of actions influences people's ascriptions of intentionality to those side effects. I present the paradigmatic cases that elicit what has been called the Knobe effect and offer some explanations of the Knobe effect. I put these explanations into two broad groups. One explains the Knobe effect by referring to our concept of intentional action. The other explains the Knobe effect without referring to our concept of intentional (...) action. I discuss some problems with these explanations and conclude with some possible avenues for future research. (shrink)

George Bealer argues that intuitions are not only reliable indicators of truth, they are necessary to the philosophical endeavor. Specifically, he thinks that intuitions are essential sources of evidence for epistemic justification. I argue that Bealer's defense of intuitions either (1) is insufficient to show that actual human beings are in a position to use intuitions for epistemic justification, or (2) begs the question. The growing empirical data about our intuitions support the view that humans are not creatures appropriately positioned (...) to use intuitions for epistemic justification in the way Bealer suggests. Without the appropriate empirical evidence that humans are beings so positioned, his view begs the question against those who think that intuitions are not reliable guides to truth. (shrink)

Recent empirical work calls into question the so-called Simple View that an agent who A’s intentionally intends to A. In experimental studies, ordinary speakers frequently assent to claims that, in certain cases, agents who knowingly behave wrongly intentionally bring about the harm they do; yet the speakers tend to deny that it was the intention of those agents to cause the harm. This paper reports two additional studies that at first appear to support the original ones, but argues that in (...) fact, the evidence of all the studies considered is best understood in terms of the Simple View. (shrink)

Heritable personality traits often predict fundamental philosophical disagreement. This conclusion is based on studies of more than 15,000 people sampled from diverse cultures and educational backgrounds, including verifiable experts. In this chapter, we review some of this research showing links between personality and philosophical bias in free will, intentional action, and ethics. Our discussion focuses on serious challenges that these philosophical biases pose (e.g., limits on the use of philosophical intuitions as evidence). We close with discussion of the Philosophical Personality (...) Argument and brief consideration of emerging projects in applied experimental philosophy. (shrink)

Cognitive scientists have been debating how the folk concept of intentional action works. We suggest a simple account: people consider that an agent did X intentionally to the extent that X was causally dependent on how much the agent wanted X to happen (or not to happen). Combined with recent models of human causal cognition, this definition provides a good account of the way people use the concept of intentional action, and offers natural explanations for puzzling phenomena such as the (...) side-effect effect. We provide empirical support for our theory, in studies where we show that people’s causation and intentionality judgments track each other closely, in everyday situations as well as in scenarios with unusual causal structures. Study 5 additionally shows that the effect of norm violations on intentionality judgments depends on the causal structure of the situation, in a way uniquely predicted by our theory. Taken together, these results suggest that the folk concept of intentional action has been difficult to define because it is made of cognitive building blocks, such as our intuitive concept of causation, whose logic cognitive scientists are just starting to understand. (shrink)

Empirical support is offered for the claim that the original Knobe effect, whereby our intentional action ascriptions exhibit certain asymmetries in light of our moral attitudes, can be successfully cancelled. This is predicted by the view that the Knobe effect can be explained in purely pragmatic terms (Adams and Steadman 2004a, 2004b, 2007). However, previous cancelling studies (Adams and Steadman 2007; Nichols and Ulatowski 2007) have failed to identify evidence of cancellability. The key to the successful cancelling strategy presented here (...) is to provide subjects with the opportunity to assent to statements that involve sufficiently strong forms of moral censure. (shrink)

Several studies have shown that people are more likely to attribute intentionality and blame to agents who perform actions that have harmful consequences. This kind of bias has problematic implications for jury decisions because it predicts that judgment in juries will malfunction if an action has a blameworthy effect. Most of these studies include in their design a vignette in which it is clear that agents have foreknowledge of the effects of their actions. This kind of design fails to replicate (...) trial situations where, in most cases, it is impossible to know with certainty whether agents have foreknowledge of the effects of their actions. In the present study, we adopt an alternative design that includes vignettes in which there is no direct evidence of foreknowledge to investigate the relationship between intentionality and blame in actions that have harmful and helpful effects. We find that people are still more likely to attribute intentionality to actions that produce harmful effects than actions that produce good effects. However, we find that people tend to attribute more blame when they have direct evidence of foreknowledge than when presented with an alternative design that does not include foreknowledge. Results indicate the relevant role that evidence of foreknowledge plays in experimental designs that study blame attribution. (shrink)

A coherent practice of mens rea (‘guilty mind’) ascription in criminal law presupposes a concept of mens rea which is insensitive to the moral valence of an action’s outcome. For instance, an assessment of whether an agent harmed another person intentionally should be unaffected by the severity of harm done. Ascriptions of intentionality made by laypeople, however, are subject to a strong outcome bias. As demonstrated by the Knobe effect, a knowingly incurred negative side effect is standardly judged intentional, whereas (...) a positive side effect is not. We report the first empirical investigation into intentionality ascriptions made by professional judges, which finds (i) that professionals are sensitive to the moral valence of outcome type, and (ii) that the worse the outcome, the higher the propensity to ascribe intentionality. The data shows the intentionality ascriptions of professional judges to be inconsistent with the concept of mens rea supposedly at the foundation of criminal law. (shrink)

This article explores whether perspective taking has an impact on the ascription of epistemic states. To do so, a new method is introduced which incites participants to imagine themselves in the position of the protagonist of a short vignette and to judge from her perspective. In a series of experiments, perspective proves to have a significant impact on belief ascriptions, but not on knowledge ascriptions. For belief, perspective is further found to moderate the epistemic side-effect effect significantly. It is hypothesized (...) that the surprising findings are driven by the special epistemic authority we enjoy in assessing our own belief states, which does not extend to the assessment of our own knowledge states. (shrink)

Experimental philosophers have investigated various ways in which non‐epistemic evaluations can affect knowledge attributions. For example, several teams of researchers (Beebe and Buckwalter 2010; Beebe and Jensen 2012; Schaffer and Knobe 2012; Beebe and Shea 2013; Buckwalter 2014b; Turri 2014) report that the goodness or badness of an agent’s action can affect whether the agent is taken to have certain kinds of knowledge. These findings raise important questions about how patterns of folk knowledge attributions should influence philosophical theorizing about knowledge.

Based on a puzzling pattern in our judgements about intentional action, Knobe [. “Intentional Action and Side-Effects in Ordinary Language.” Analysis 63: 190–194] has claimed that these judgements are shaped by our moral judgements and evaluations. However, this claim goes directly against a key conceptual intuition about intentional action – the “frame-of-mind condition”, according to which judgements about intentional action are about the agent’s frame-of-mind and not about the moral value of his action. To preserve this intuition Hindriks [. “Intentional (...) Action and the Praise-Blame Asymmetry.” The Philosophical Quarterly 58: 630–641;. “Normativity in Action: How to Explain the Knobe Effect and its Relatives.” Mind & Language 29: 51–72] has proposed an alternate account of the Knobe Effect. According to his “Normative Reason account of Intentional Action”, a side-effect counts as intentional only when the agent thought it constituted a normative reason not to act but did not care. In... (shrink)

Knobe (Analysis 63:190-193, 2003a, Philosophical Psychology 16:309-324, 2003b, Analysis 64:181-187, 2004b) found that people are more likely to attribute intentionality to agents whose actions resulted in negative side-effects that to agents whose actions resulted in positive ones. Subsequent investigation has extended this result to a variety of other folk psychological attributions. The present article reports experimental findings that demonstrate an analogous effect for belief ascriptions. Participants were found to be more likely to ascribe belief, higher degrees of belief, higher degrees (...) of rational belief, and dispositional belief to agents in central Knobe effect cases who bring about negative side-effects than to agents who bring about positive ones. These findings present a significant challenge to widely held views about the Knobe effect, since many explanations of it assume that agents in contrasting pairs of Knobe effect cases do not differ with respect to their beliefs. Participants were also found to be more confident that knowledge should be attributed than they were that belief or dispositional belief should be attributed. This finding strengthens the challenge that Myers-Schulz and Schwitzgebel (2013) have launched against the traditional view that knowledge entails belief. (shrink)

Skill or control is commonly regarded as a necessary condition for intentional action. This received wisdom is challenged by experiments conducted by Joshua Knobe and Thomas Nadelhoffer, which suggest that moral considerations sometimes trump considerations of skill and control. I argue that this effect (as well as the Knobe effect) can be explained in terms of the role normative reasons play in the concept of intentional action. This explanation has significant advantages over its rivals. It involves at most a conservative (...) extension rather than a radical revision of what we tend to believe about intentional action, and it fits better with the way we conceive of the relation between intentional action and moral responsibility. (shrink)

Shows that the very same asymmetries that arise for intentionally also arise from deciding, desiring, in favor of, opposed to, and advocating. It seems that the phenomenon is not due to anything about the concept of intentional action in particular. Rather, the effects observed for the concept of intentional action should be regarded as just one manifestation of the pervasive impact of moral judgment.

In “Intentional action and side-effects in ordinary language” (2003), Joshua Knobe reported an asymmetry in test subjects’ responses to a question about intentionality: subjects are more likely to judge that a side effect of an agent’s intended action is intentional if they think the side effect is morally bad than if they think it is morally good. This result has been taken to suggest that the concept of intentionality is an inherently moral concept. In this paper, we draw attention to (...) the fact that Knobe’s original interpretation of the results is based on an abstract rendering of the central scenario that is significantly different from the vignettes presented to the survey participants. In particular, the experimental vignettes involve temporal and social dimensions; they portray sequences of social actions involving an agent and an interlocutor, rather than a lone agent making a momentary decision in light of certain attitudes. Through textual analyses of a set of vignettes used to study the Knobe effect, drawing on ethnomethodology, conversation analysis, and discursive psychology, we show that there are many differences between the experimental conditions besides the moral valence of the side effect. In light of our textual analyses, we discuss vignette methodology in experimental philosophy and suggest an alternative interpretation of Knobe’s original experimental results. We also argue that experimental philosophy could benefit from considering research on naturally occurring social interaction as an alternative source of empirical findings for discussions of folk-psychological concepts. (shrink)

In a celebrated experiment, Joshua Knobe showed that people are much more prone to attribute intentionality to an agent for a side effect of a given act when that side effect is harmful than when it is beneficial. This asymmetry has become known as ‘the Knobe Effect’. According to Knobe's Moral Valence Explanation, bad effects trigger the attributions of intentionality, whereas good effects do not. Many others believe that the Knobe Effect is best explained in terms of the high amount (...) of blame attributed in the harm condition, and the low amount of praise attributed in the help condition. This Blame Hypothesis explains the high number of intentionality attributions in the harm condition in terms of the high degree of blame people ascribe, and the low number of intentionality attributions in the help conditions in terms of the low degree of praise people attribute. We replicated Knobe's original experiment and conducted a logistic regression on the results to probe more deeply into the relationship between attributions of intentionality and responsibility. The statistical analysis revealed a hitherto unknown interaction effect: intentionality correlates with blame, but not with praise. This interaction effect is consistent with the Moral Valence Hypothesis, but inconsistent with the Blame Hypothesis, as well as with two of the three other hypotheses discussed here. (shrink)

People’s moral judgments affect their judgments of intentionality for actions that succeeded by luck. This article aimed to explain that phenomenon by suggesting that people’s judgments of intentionality are driven by the underlying questions they have considered. We examined two types of questions: questions about why people act, and questions about how they succeed in acting. In a series of experiments, we found that people prefer different questions for neutral and immoral actions (Studies 1 and 2) and that asking them (...) to think about questions they would not have preferred can change their judgments of intentionality (Study 3). These experiments suggest that neutral actions are judged to be less intentional simply because they do not motivate observers to ask questions which draw attention to the actor’s mental states. We discuss the potential application of this framework to other concepts affected by morality in surprising ways, such as causality. (shrink)

Extant models of moral judgment assume that an action’s intentionality precedes assignments of blame. Knobe (2003b) challenged this fundamental order and proposed instead that the badness or blameworthiness of an action directs (and thus unduly biases) people’s intentionality judgments. His and other researchers’ studies suggested that blameworthy actions are considered intentional even when the agent lacks skill (e.g., killing somebody with a lucky shot) whereas equivalent neutral actions are not (e.g., luckily hitting a bull’s-eye). The present five studies offer an (...) alternative account of these provocative findings. We suggest that people see the morally significant action examined in previous studies (killing) as accomplished by a basic action (pressing the trigger) for which an unskilled agent still has sufficient skill. Studies 1 through 3 show that when this basic action is performed unskillfully or is absent, people are far less likely to view the killing as intentional, demonstrating that intentionality judgments, even about immoral actions, are guided by skill information. Studies 4 and 5 further show that a neutral action such as hitting the bull’s-eye is more difficult than killing and that difficult actions are less often judged intentional. When difficulty is held constant, people’s intentionality judgments are fully responsive to skill information regardless of moral valence. The present studies thus speak against the hypothesis of a moral evaluation bias in intentionality judgments and instead document people’s sensitivity to subtle features of human action. (shrink)

Ratio Juris, Volume 35, Issue 2, Page 191-222, June 2022.

The concept of intention is widely thought to involve a confidence condition of some sort, a condition that specifies certain beliefs that one must either have or lack if one intends to do something. Two of the most common formulations of this condition are the following: (i) A intends to X only if A believes that they (probably) will X; and (ii) A intends to X only if A does not believe that they (probably) will not X. A third, much (...) weaker formulation can also be considered: (iii) A intends to X only if A does not believe that it is highly unlikely that they will X. In this article I report on a series of experiments that indicate that ordinary speakers of English do not apply the concepts of intention and belief in accordance with any of the foregoing hypotheses. These experimental results provide empirical evidence against the idea that there is a confidence condition in the concept of intention. (shrink)

Studies designed to help us understand how nonspecialists conceive of intentional action have generated some widely discussed results. To what extent are the results accounted for by the existence of different folk conceptions of intentional action? That is my guiding question in this article. I am not in a position to offer a full answer, but I do hope to make some progress.

Research has consistently shown that people consider harmful side effects of an action more intentional than helpful side effects. This phenomenon is known as the side- effect effect (SEE), which refers to the influence of moral considerations in judgments of intentionality and other non-moral concepts. There is an ongoing debate about how to explain this asymmetric pattern of judgment and the psychological factors involved in it. It has been posited that affective reactions to agents that bring about harmful side- effects (...) could bias intentionality attributions in these cases, explaining the asymmetric pattern of intentionality judgments that we observe in the SEE. We call this the affective bias hypothesis (ABH). Evidence for the ABH is mixed, with some findings suggesting a role for affective processes, while others suggesting that affective processes play no role in the SEE. A possible explanation for these apparently contradictory results points to affective processes involved in the SEE being confined to anger. In a series of empirical studies, we systematically measured and manipulated participants’ anger in order to test this possibility. Our findings suggest that anger play no role in intentionality judgments in SEE cases, while providing support for a non-emotional motivation to blame as a factor underlying the SEE. (shrink)

This paper concerns a recently discovered, puzzling asymmetry in judgments of whether an action is intentional or not (Knobe, Philosophical Psychology 16:309–324, 2003a ; Analysis 63:190–193, b ). We report new data replicating the asymmetry in the context of scenarios wherein an agent achieves an amoral or immoral goal due to luck. Participants’ justifications of their judgments of the intentionality of the agent’s action indicate that two distinct folk concepts of intentional action played a role in their judgments. When viewed (...) from this perspective, the puzzle disappears, although the asymmetry remains. (shrink)

In this paper, we argue that the so-called Knobe-Effect constitutes an error. There is now a wealth of data confirming that people are highly prone to what has also come to be known as the ‘side-effect effect’. That is, when attributing psychological states—such as intentionality, foreknowledge, and desiring—as well as other agential features—such as causal control—people typically do so to a greater extent when the action under consideration is evaluated negatively. There are a plethora of models attempting to account for (...) this effect. We hold that the central question of interest is whether the effect represents a competence or an error in judgment. We offer a systematic argument for the claim that the burden of proof regarding this question is on the competence theorist. We sketch an account, based on the notion of the reactive attitudes, that can accommodate both the idea that these sorts of judgments are fundamentally normative and that they often constitute errors. (shrink)

We explore and provide an account for a recently identified judgment anomaly, i.e., an order effect that changes the strength of intentionality ascriptions for some side effects (e.g., when a chairman's pursuit of profits has the foreseen but unintended consequence of harming the environment). Experiment 1 replicated the previously unanticipated order effect anomaly controlling for general individual differences. Experiment 2 revealed that the order effect was multiply determined and influenced by factors such as beliefs (i.e., that the same actor was (...) involved in bringing about both good and bad side effects) and philosophical training (i.e., more training was associated with smaller differences in judgment when harm followed help). Results provide more evidence that the folk's philosophically relevant intuitions are predictably fragmented and depend on the dynamic interplay between persons, process, and environments. Methodological and theoretical implications are discussed. (shrink)