The know-how solution to Kraemer's puzzle.

In certain cases, people judge that agents bring about ends intentionally but also that they do not bring about the means that brought about those ends intentionally-even though bringing about the ends and means is just as likely. We call this difference in judgments the Kraemer effect. We offer a novel explanation for this effect: a perceived difference in the extent to which agents know how to bring about the means and the ends explains the Kraemer effect. In several experiments, we replicate the Kraemer effect in a variety of non-moral and moral scenarios, and we find support for our new account. This work accords with a burgeoning area of action theory that identifies an important connection between know-how and intentionality.

Double Prevention, Causal Judgments, and Counterfactuals.

Mike accidentally knocked against a bottle. Seeing that the bottle was about to fall, Jack was just about to catch it when Peter accidentally knocked against him, making Jack unable to catch it. Jack did not grab the bottle, and it fell to the ground and spilled. In double-prevention cases like these, philosophers and nonphilosophers alike tend to judge that Mike knocking into the bottle caused the beer to spill and that Peter knocking into Jack did not cause the beer to spill. This difference in causal judgment is a difficult puzzle for counterfactual theories of causal judgment; if each event had not happened, the outcome would not have, yet there is a difference in people's causal judgments. In four experiments and three supplemental experiments, we confirm this difference in causal judgments. We also show that differences in people's counterfactual thinking can explain this difference in their causal judgments and that recent counterfactual models of causal judgment can account for these patterns. We discuss these results in relation to work on counterfactual thinking and causal modeling.

Confidence and gradation in causal judgment.

When comparing the roles of the lightning strike and the dry climate in causing the forest fire, one might think that the lightning strike is more of a cause than the dry climate, or one might think that the lightning strike completely caused the fire while the dry conditions did not cause it at all. Psychologists and philosophers have long debated whether such causal judgments are graded; that is, whether people treat some causes as stronger than others. To address this debate, we first reanalyzed data from four recent studies. We found that causal judgments were actually multimodal: although most causal judgments made on a continuous scale were categorical, there was also some gradation. We then tested two competing explanations for this gradation: the confidence explanation, which states that people make graded causal judgments because they have varying degrees of belief in causal relations, and the strength explanation, which states that people make graded causal judgments because they believe that causation itself is graded. Experiment 1 tested the confidence explanation and showed that gradation in causal judgments was indeed moderated by confidence: people tended to make graded causal judgments when they were unconfident, but they tended to make more categorical causal judgments when they were confident. Experiment 2 tested the causal strength explanation and showed that although confidence still explained variation in causal judgments, it did not explain away the effects of normality, causal structure, or the number of candidate causes. Overall, we found that causal judgments were multimodal and that people make graded judgments both when they think a cause is weak and when they are uncertain about its causal role.

8,000 years of climate, vegetation, fire and land-use dynamics in the thermo-mediterranean vegetation belt of northern Sardinia (Italy).

Knowledge about the vegetation history of Sardinia, the second largest island of the Mediterranean, is scanty. Here, we present a new sedimentary record covering the past ~ 8,000 years from Lago di Baratz, north-west Sardinia. Vegetation and fire history are reconstructed by pollen, spores, macrofossils and charcoal analyses and environmental dynamics by high-resolution element geochemistry together with pigment analyses. During the period 8,100-7,500 cal bp, when seasonality was high and fire and erosion were frequent, Erica arborea and E. scoparia woodlands dominated the coastal landscape. Subsequently, between 7,500 and 5,500 cal bp, seasonality gradually declined and thermo-mediterranean woodlands with Pistacia and Quercus ilex partially replaced Erica communities under diminished incidence of fire. After 5,500 cal bp, evergreen oak forests expanded markedly, erosion declined and lake levels increased, likely in response to increasing (summer) moisture availability. Increased anthropogenic fire disturbance triggered shrubland expansions (e.g. Tamarix and Pistacia) around 5,000-4,500 cal bp. Subsequently around 4,000-3,500 cal bp evergreen oak-olive forests expanded massively when fire activity declined and lake productivity and anoxia reached Holocene maxima. Land-use activities during the past 4,000 years (since the Bronze Age) gradually disrupted coastal forests, but relict stands persisted under rather stable environmental conditions until ca. 200 cal bp, when agricultural activities intensified and Pinus and Eucalyptus were planted to stabilize the sand dunes. Pervasive prehistoric land-use activities since at least the Bronze Age Nuraghi period included the cultivation of Prunus, Olea europaea and Juglans regia after 3,500-3,300 cal bp, and Quercus suber after 2,500 cal bp. We conclude that restoring less flammable native Q. ilex and O. europaea forest communities would markedly reduce fire risk and erodibility compared to recent forest plantations with flammable non-native trees (e.g. Pinus, Eucalyptus) and xerophytic shrubland (e.g. Cistus, Erica).

Making moral principles suit yourself.

Normative ethical theories and religious traditions offer general moral principles for people to follow. These moral principles are typically meant to be fixed and rigid, offering reliable guides for moral judgment and decision-making. In two preregistered studies, we found consistent evidence that agreement with general moral principles shifted depending upon events recently accessed in memory. After recalling their own personal violations of moral principles, participants agreed less strongly with those very principles-relative to participants who recalled events in which other people violated the principles. This shift in agreement was explained, in part, by people's willingness to excuse their own moral transgressions, but not the transgressions of others. These results have important implications for understanding the roles memory and personal identity in moral judgment. People's commitment to moral principles may be maintained when they recall others' past violations, but their commitment may wane when they recall their own violations.

Counterfactual thinking and recency effects in causal judgment.

People tend to judge more recent events, relative to earlier ones, as the cause of some particular outcome. For instance, people are more inclined to judge that the last basket, rather than the first, caused the team to win the basketball game. This recency effect, however, reverses in cases of overdetermination: people judge that earlier events, rather than more recent ones, caused the outcome when the event is individually sufficient but not individually necessary for the outcome. In five experiments (N = 5507), we find evidence for the recency effect and the primacy effect for causal judgment. Traditionally, these effects have been a problem for counterfactual views of causal judgment. However, we argue that an extension of a recent counterfactual model of causal judgment explains both the recency and the primacy effect. In line with the predictions of our extended counterfactual model, we also find that, regardless of causal structure, people tend to imagine the counterfactual alternative to the more recent event rather than to the earlier one. Moreover, manipulating this tendency affects causal judgments in the ways predicted by this extended model: asking participants to imagine the counterfactual alternative to the earlier event weakens the interaction between recency and causal structure, and asking participants to imagine the counterfactual alternative to the more recent event strengthens the interaction between recency and causal structure. We discuss these results in relation to work on counterfactual thinking, causal modeling, and late-preemption.

Perceived similarity of imagined possible worlds affects judgments of counterfactual plausibility.

People frequently entertain counterfactual thoughts, or mental simulations about alternative ways the world could have been. But the perceived plausibility of those counterfactual thoughts varies widely. The current article interfaces research in the philosophy and semantics of counterfactual statements with the psychology of mental simulations, and it explores the role of perceived similarity in judgments of counterfactual plausibility. We report results from seven studies (N = 6405) jointly supporting three interconnected claims. First, the perceived plausibility of a counterfactual event is predicted by the perceived similarity between the possible world in which the imagined situation is thought to occur and the actual world. Second, when people attend to differences between imagined possible worlds and the actual world, they think of the imagined possible worlds as less similar to the actual world and tend to judge counterfactuals in such worlds as less plausible. Lastly, when people attend to what is identical between imagined possible worlds and the actual world, they think of the imagined possible worlds as more similar to the actual world and tend to judge counterfactuals in such worlds as more plausible. We discuss these results in light of philosophical, semantic, and psychological theories of counterfactual thinking.

Norms Affect Prospective Causal Judgments.

People more frequently select norm-violating factors, relative to norm-conforming ones, as the cause of some outcome. Until recently, this abnormal-selection effect has been studied using retrospective vignette-based paradigms. We use a novel set of video stimuli to investigate this effect for prospective causal judgments-that is, judgments about the cause of some future outcome. Four experiments show that people more frequently select norm-violating factors, relative to norm-conforming ones, as the cause of some future outcome. We show that the abnormal-selection effects are not primarily explained by the perception of agency (Experiment 4). We discuss these results in relation to recent efforts to model causal judgment.

Estimating burn severity and carbon emissions from a historic megafire in boreal forests of China.

Wildfires, especially those of large size, worsen air quality and alter the carbon cycle through combustion of large quantities of biomass and release of carbon into the atmosphere. The Black Dragon fire, which occurred in 1987 in the boreal forests of China is among the top five of such megafires ever recorded in the world. With over 30 years of accumulation of data and availability of new greenhouse gas emission accounting methods, carbon emissions from this megafire can now be estimated with improved precision and greater spatial resolution. To do this, we combined field and remote sensing data to map four burn severity classes and calculated combustion efficiency in terms of the biomass immediately consumed in the fire. Results of the study showed that 1.30 million hectares burned and 52% of that area burned with high severity. The emitted carbon dioxide equivalents (CO2e), accounted for approximately 10% of total fossil fuel emissions from China in 1987, along with CO (2%-3% of annual anthropogenic CO emissions from China) and non-methane hydrocarbons (NMHC) contributing to the atmospheric pollutants. Our study provides an important basis for carbon emission estimation and understanding the impacts of megafires.

A counterfactual explanation for the action effect in causal judgment.

People's causal judgments are susceptible to the action effect, whereby they judge actions to be more causal than inactions. We offer a new explanation for this effect, the counterfactual explanation: people judge actions to be more causal than inactions because they are more inclined to consider the counterfactual alternatives to actions than to consider counterfactual alternatives to inactions. Experiment 1a conceptually replicates the original action effect for causal judgments. Experiment 1b confirms a novel prediction of the new explanation, the reverse action effect, in which people judge inactions to be more causal than actions in overdetermination cases. Experiment 2 directly compares the two effects in joint-causation and overdetermination scenarios and conceptually replicates them with new scenarios. Taken together, these studies provide support for the new counterfactual explanation for the action effect in causal judgment.

Remembering moral and immoral actions in constructing the self.

Having positive moral traits is central to one's sense of self, and people generally are motivated to maintain a positive view of the self in the present. But it remains unclear how people foster a positive, morally good view of the self in the present. We suggest that recollecting and reflecting on moral and immoral actions from the personal past jointly help to construct a morally good view of the current self in complementary ways. More specifically, across four studies we investigated the extent to which people believe they have changed over time after recollecting their own moral or immoral behaviors from the personal past. Our results indicate that recollecting past immoral actions is associated with stronger impressions of dissimilarity and change in the sense of self over time than recollecting past moral actions. These effects held for diverse domains of morality (i.e., honesty/dishonesty, helping/harming, fairness/unfairness, and loyalty/disloyalty), and they remained even after accounting for objective, calendar time. Further supporting a motivational explanation, these effects held when people recollected their own past actions but not when they recollected the actions of other people.

Reasons probably won't change your mind: The role of reasons in revising moral decisions.

Although many philosophers argue that making and revising moral decisions ought to be a matter of deliberating over reasons, the extent to which the consideration of reasons informs people's moral decisions and prompts them to change their decisions remains unclear. Here, after making an initial decision in 2-option moral dilemmas, participants examined reasons for only the option initially chosen (affirming reasons), reasons for only the option not initially chosen (opposing reasons), or reasons for both options. Although participants were more likely to change their initial decisions when presented with only opposing reasons compared with only affirming reasons, these effect sizes were consistently small. After evaluating reasons, participants were significantly more likely not to change their initial decisions than to change them, regardless of the set of reasons they considered. The initial decision accounted for most of the variance in predicting the final decision, whereas the reasons evaluated accounted for a relatively small proportion of the variance in predicting the final decision. This resistance to changing moral decisions is at least partly attributable to a biased, motivated evaluation of the available reasons: participants rated the reasons supporting their initial decisions more favorably than the reasons opposing their initial decisions, regardless of the reported strategy used to make the initial decision. Overall, our results suggest that the consideration of reasons rarely induces people to change their initial decisions in moral dilemmas. (PsycINFO Database Record

I'm not the person I used to be: The self and autobiographical memories of immoral actions.

People maintain a positive identity in at least two ways: They evaluate themselves more favorably than other people, and they judge themselves to be better now than they were in the past. Both strategies rely on autobiographical memories. The authors investigate the role of autobiographical memories of lying and emotional harm in maintaining a positive identity. For memories of lying to or emotionally harming others, participants judge their own actions as less morally wrong and less negative than those in which other people lied to or emotionally harmed them. Furthermore, people judge those actions that happened further in the past to be more morally wrong than those that happened more recently. Finally, for periods of the past when they believed that they were very different people than they are now, participants judge their actions to be more morally wrong and more negative than those actions from periods of their pasts when they believed that they were very similar to who they are now. The authors discuss these findings in relation to theories about the function of autobiographical memory and moral cognition in constructing and perceiving the self over time. (PsycINFO Database Record

Blame, not ability, impacts moral "ought" judgments for impossible actions: Toward an empirical refutation of "ought" implies "can".

Recently, psychologists have explored moral concepts including obligation, blame, and ability. While little empirical work has studied the relationships among these concepts, philosophers have widely assumed such a relationship in the principle that "ought" implies "can," which states that if someone ought to do something, then they must be able to do it. The cognitive underpinnings of these concepts are tested in the three experiments reported here. In Experiment 1, most participants judge that an agent ought to keep a promise that he is unable to keep, but only when he is to blame for the inability. Experiment 2 shows that such "ought" judgments correlate with judgments of blame, rather than with judgments of the agent's ability. Experiment 3 replicates these findings for moral "ought" judgments and finds that they do not hold for nonmoral "ought" judgments, such as what someone ought to do to fulfill their desires. These results together show that folk moral judgments do not conform to a widely assumed philosophical principle that "ought" implies "can." Instead, judgments of blame play a modulatory role in some judgments of obligation.

Past and future evolution of Abies alba forests in Europe - comparison of a dynamic vegetation model with palaeo data and observations.

Information on how species distributions and ecosystem services are impacted by anthropogenic climate change is important for adaptation planning. Palaeo data suggest that Abies alba formed forests under significantly warmer-than-present conditions in Europe and might be a native substitute for widespread drought-sensitive temperate and boreal tree species such as beech (Fagus sylvatica) and spruce (Picea abies) under future global warming conditions. Here, we combine pollen and macrofossil data, modern observations, and results from transient simulations with the LPX-Bern dynamic global vegetation model to assess past and future distributions of A. alba in Europe. LPX-Bern is forced with climate anomalies from a run over the past 21 000 years with the Community Earth System Model, modern climatology, and with 21st-century multimodel ensemble results for the high-emission RCP8.5 and the stringent mitigation RCP2.6 pathway. The simulated distribution for present climate encompasses the modern range of A. alba, with the model exceeding the present distribution in north-western and southern Europe. Mid-Holocene pollen data and model results agree for southern Europe, suggesting that at present, human impacts suppress the distribution in southern Europe. Pollen and model results both show range expansion starting during the Bølling-Allerød warm period, interrupted by the Younger Dryas cold, and resuming during the Holocene. The distribution of A. alba expands to the north-east in all future scenarios, whereas the potential (currently unrealized) range would be substantially reduced in southern Europe under RCP8.5. A. alba maintains its current range in central Europe despite competition by other thermophilous tree species. Our combined palaeoecological and model evidence suggest that A. alba may ensure important ecosystem services including stand and slope stability, infrastructure protection, and carbon sequestration under significantly warmer-than-present conditions in central Europe.

Climate refugia: joint inference from fossil records, species distribution models and phylogeography.

Climate refugia, locations where taxa survive periods of regionally adverse climate, are thought to be critical for maintaining biodiversity through the glacial-interglacial climate changes of the Quaternary. A critical research need is to better integrate and reconcile the three major lines of evidence used to infer the existence of past refugia - fossil records, species distribution models and phylogeographic surveys - in order to characterize the complex spatiotemporal trajectories of species and populations in and out of refugia. Here we review the complementary strengths, limitations and new advances for these three approaches. We provide case studies to illustrate their combined application, and point the way towards new opportunities for synthesizing these disparate lines of evidence. Case studies with European beech, Qinghai spruce and Douglas-fir illustrate how the combination of these three approaches successfully resolves complex species histories not attainable from any one approach. Promising new statistical techniques can capitalize on the strengths of each method and provide a robust quantitative reconstruction of species history. Studying past refugia can help identify contemporary refugia and clarify their conservation significance, in particular by elucidating the fine-scale processes and the particular geographic locations that buffer species against rapidly changing climate.

A model-data comparison of Holocene timberline changes in the Swiss Alps reveals past and future drivers of mountain forest dynamics.

Mountain vegetation is strongly affected by temperature and is expected to shift upwards with climate change. Dynamic vegetation models are often used to assess the impact of climate on vegetation and model output can be compared with paleobotanical data as a reality check. Recent paleoecological studies have revealed regional variation in the upward shift of timberlines in the Northern and Central European Alps in response to rapid warming at the Younger Dryas/Preboreal transition ca. 11 700 years ago, probably caused by a climatic gradient across the Alps. This contrasts with previous studies that successfully simulated the early Holocene afforestation in the (warmer) Central Alps with a chironomid-inferred temperature reconstruction from the (colder) Northern Alps. We use LandClim, a dynamic landscape vegetation model to simulate mountain forests under different temperature, soil and precipitation scenarios around Iffigsee (2065 m a.s.l.) a lake in the Northwestern Swiss Alps, and compare the model output with the paleobotanical records. The model clearly overestimates the upward shift of timberline in a climate scenario that applies chironomid-inferred July-temperature anomalies to all months. However, forest establishment at 9800 cal. BP at Iffigsee is successfully simulated with lower moisture availability and monthly temperatures corrected for stronger seasonality during the early Holocene. The model-data comparison reveals a contraction in the realized niche of Abies alba due to the prominent role of anthropogenic disturbance after ca. 5000 cal. BP, which has important implications for species distribution models (SDMs) that rely on equilibrium with climate and niche stability. Under future climate projections, LandClim indicates a rapid upward shift of mountain vegetation belts by ca. 500 m and treeline positions of ca. 2500 m a.s.l. by the end of this century. Resulting biodiversity losses in the alpine vegetation belt might be mitigated with low-impact pastoralism to preserve species-rich alpine meadows.