Small-scale gold mining and the COVID-19 pandemic: Conflict and cooperation in the Brazilian Amazon

The COVID-19 pandemic exposes both conflict and cooperation in artisanal and small-scale gold mining in the Brazilian Amazon. Reporting on the experiences of artisanal and small-scale gold miners (garimpeiros, in Brazilian Portuguese), we show how, on the one hand, the pandemic challenges an already precarious working system that could lead garimpeiros, often invisible to public policies, to positions of further vulnerability; and, on the other hand, highlights the capacity of garimpeiros to self-organize and navigate the difficulties by finding alternative solutions to cope with the crisis. This leads us to argue that emerging strategies of cooperation, related to self-organization and communication channels have the potential to provide experiences useful for processes of conflict transformation in the post-crisis. We acknowledge that much depends on the severity of the crisis and its manifestations in the region; nevertheless, the potential for constructive outcomes from the crisis should not be disregarded.

Relative to what? Dynamic updating of fluency standards and between-participants illusions of truth

Previous research has shown that fluency effects are driven by discrepancies between current and baseline fluency. Thus, illusions of truth associated with repetition (which increases statement fluency and its perceived truth-value relative to new statements) are less likely to occur when participants judge pure lists of either all-repeated or all-new statements and comparisons are between-participants, than when participants judge mixed lists and comparisons are within-participants. Still, there are demonstrations of between-participants illusions of truth in the literature. In this manuscript, we explain the emergence of between-participants truth effects in terms of hypothetical dynamic updating of fluency standards. The findings of two experiments provide evidence for this hypothesis by showing that between-participants truth effects occur most strongly for the first elements of the statement list but are reduced over time. The findings suggest that the dynamics of fluency experiences contribute to the truth effect and should be taken into account when investigating illusions of truth.

The attractiveness-positivity link: Let's contextualize it

The statement "what is beautiful is good" reflects a persuasive heuristic that may be supported either by a general association of attractiveness with positivity or by a specific association with the perceived credibility of an attractive source. In one study (N = 58), we approach this question using an explicit and an implicit measure (Stroop Task) to assess whether attractiveness is more likely associated with valenced words when these are related (vs. unrelated) to credibility. Results show that this effect occurs but only for the implicit measure. When the word-face associations were made at an explicit level, we found a general association between positivity and attractiveness, unrestricted to the dimension of credibility. We discuss how these results inform about attractiveness as a shortcut to judgments of validity.

Molt-related and size-dependent differences in the escape response and post-threat behavior of the American lobster, Homarus americanus

Videotaped recordings of adult lobsters of different molt stages were analyzed. The escape response of adults was compared with that of juveniles recorded in an earlier study. Juvenile lobsters always respond to a threat with escape behavior irrespective of their molt stage, but in adults the probability of eliciting a response was a function of molt stage: more hard-shelled (intermolt stage C) and (premolt stage D) animals tailflipped than did soft-shelled (postmolt stages A and B) animals. The number, frequency, and duration of tailflips, and the average distance swum by animals in each molt stage were measured for the entire escape response, for the initial power swim, and for the subsequent swims. These measurements were used to compute several parameters: velocity, acceleration, force, and work; average distance traveled in a tailflip for each kilogram of body weight (distance/kg/tailflip); and average distance traveled for each bodylength (distance/bodylength). Among adults, intermolt (stage C) lobsters traveled significantly farther and faster than postmolt animals (stages A and B). Among juveniles, late postmolt (stage B) animals traveled farther. Among adults, although the total number of tailflips and the duration of the response were not significantly different among molt stages, the number of tailflips/second (frequency) and distance traveled/kg/tailflip were greater for intermolt animals. In juvenile intermolts, however, frequency and distance/kg/tailflip were markedly lower than in the premolt stages. Although values were lower than intermolts and premolts, postmolt adults sustained their swimming frequency, distance/kg/tailflip, and distance/bodylength for the entire escape distance (as did postmolt juveniles). These parameters then dropped off sharply for both adult and juvenile intermolt and premolt animals in the second half of the escape distance. Post-threat behaviors reveal that stage D animals have the highest aggression index and often attack the presented stimulus, whereas stage A animals are the least likely to approach the stimulus and typically back away in a non-aggressive posture. Thus, although effects of the molt cycle on adult and juvenile escape behavior are similar in some ways, other physical characteristics of adults, such as weight, allometry, and physiology, seem to become important in determining the likelihood of escape behavior and the characteristics of the escape swim in each molt stage.

Time in residence affects escape and agonistic behavior in adult male american lobsters

Acquisition and retention of a shelter by a lobster are two of the variables that play a role in lobster agonistic interactions. Since shelter procurement and retention are important for lobster survival, behaviors related to this activity frequently outrank other daily behaviors (e.g., searching for food). Here, we examine the effects of time in residence on the parameters of the escape response of the American lobster, Homarus americanus. Adult male intermolt lobsters (Stage C4) were placed in an experimental tank for three different time periods (one hour, 24 hours, and 48 hours). The probability of eliciting an escape response was inversely related to the time spent in the tank. Eighty percent of the animals in residence for 1 h tailflipped in response to a threat, whereas only 14% of the animals in residence for 48 h tailflipped. There were also significant changes in some of the parameters of the escape response among animals in residence for 24 h compared to those in residence for 1 h. The number of tailflips and the distance traveled were reduced, although frequency, velocity, acceleration, force, and work factors were not significantly different. Furthermore, with increased time in residence, lobsters switched from an avoidance or escape-prone behavior to an aggressive-prone behavior. Most of the animals in residence for 48 h approached and attacked a threat-stimulus rather than fleeing from it. On an empirically defined "index of aggressiveness," in which various behaviors were numerically ranked from least aggressive (0) to most aggressive (6), animals residing in the tank for 1 h had an average index value of 0.1 compared to a value of 5.0 for animals in residence for 48 h. These findings are consonant with the suggestion that lobsters that have occupied a given space for an extended period of time take possession of the site and defend it instead of fleeing when threatened with a threat-inducing stimulus; it supports the idea that shelter retention increases aggressiveness and diminishes avoidance behaviors.

Comparative Analysis of Escape Behavior in Male, and Gravid and Non-Gravid, Female Lobsters

Few studies exist in which the parameters of a single behavior have been quantitatively compared for male and female lobsters. Here, we have examined the effects of sex and gravidity on the parameters of the escape behavior of the American lobster, Homarus americanus, elicited by a visual threat. Both non-gravid females and male lobsters readily tailflipped in response to the stimulus, but gravid females failed, with one exception, to initiate a swim, even when stimulus strength was increased. Although the total distance swum by males and non-gravid females was not statistically different, males covered more ground in the initial power swim and during the subsequent swims than did non-gravid females. Males swam for a longer time, performing more tailflips, than females. Relative to their length and weight, males swam a greater distance at each stroke during the initial power swim and the subsequent swims, although, females might have compensated by swimming at a higher frequency. There were no significant differences in swimming velocity or acceleration, nor in the calculated force or work performed by the two sex classes (male and non-gravid females). Therefore, apart from egg-bearing, which severely inhibits the escape response, it remains to be seen whether the subtle physiological and anatomical sexual dimorphism that produces longer and more swim strokes in males but higher frequency tailflips in females results in the same chances of survival for the sexes.