Are We Just Going to Burn Illegal Ivory? How About Flooding the Market with Synthetic Ivory?

ON Saturday, Kenyan president Uhuru Kenyatta oversaw the destruction of over $100 Million in illegal ivory as a protest against the international ivory trade, which is slowly killing the African Elephant. As a heavily publicized international event (it was covered extensively by many news agencies, including in this piece in Sunday’s New York Times), it cannot be a bad thing to use this opportunity to raise awareness of the existential threat that poaching poses to Africa’s elephants, and I’m all for consciousness raising, but this is a half-measure at best. Can’t we do better than just grandstanding? How about driving down the value of poached ivory?

Attribution: Muhammad Mahdi Karim

Attribution: Muhammad Mahdi Karim

I think I read somewhere that the prices of goods tend to go down as the supply goes up. Is anybody talking seriously about just swamping the illegal ivory market with ivory we can make in the laboratory? I’m not just spinning a sci-fi scenario here. This company has figured out how to synthesize rhinoceros horn in the laboratory by taking the genetic code that built rhinoceros horn in actual living rhinos and using it as a set of instructions for 3-D printing. Is there some reason why the same approach could not be used to synthesize elephant ivory in the laboratory and then flood the market with it? Stiff penalties for poachers and ivory traders is certainly worth pursuing as a strategy, as is placing bans on ivory imports and exports, but why not deter poachers and traders by just flat-out removing their economic incentives?

Evidently, conservation experts are far from convinced that laboratory-synthesized rhino horn will displace the poaching industry by causing the prices to crash, and with so few rhinos left I suppose there isn’t much time for chasing options that won’t help.  Perhaps you can’t do everything at once when you’re facing a crisis as dire as the one that is facing the rhino. But honestly, it’s hard for me to see how a technological solution based on the laws of supply and demand don’t deserve some honest consideration as well as we think about saving Africa’s elephants.

The Generosity of Nations Before the Welfare State

Lange-MigrantMother02FOR the past four years or so, I have been working on a book about the evolutionary and cultural basis for humans’ generosity toward strangers. As I’ve worked to understand the major transitions in human generosity over the past few millennia, I’ve regularly lamented the fact that the quantitative data on formalized efforts to meet the needs of the poor and destitute are very poor in the historical record until around 1880. Nevertheless, I have continued to look on an almost weekly basis for new results that could help make sense of the history of human generosity before the welfare state.

This past week, I finally hit paydirt. In this new paper, Bas van Bavel and Auke Rijpma used data from a variety of historical documents to estimate the proportions of GDP devoted to formalized efforts to meet the needs of the poor in three European countries (Italy, the Netherlands, and England) going back as far as 1430. As far as I am aware, these are the oldest data on formalized poor relief that have ever been assembled. Between 1430 and 1850, it looks like these three nations had the will (and the ways) to devote about 1.5% of GDP to poor relief.

The numbers from Van Bavel and Rijpma are more or less directly comparable to the percentages of GDP that the modern OECD nations devote to so-called “social transfers.” The OECD numbers incorporate everything from health insurance to unemployment assistance to school lunches, and everything in between. Across all of the OECD nations, about 22% of GDP goes to social spending, but these numbers exclude private social spending (for example by corporations in the forms of health insurance and retirement pensions for workers, which are particularly important sources of social spending in the UK, the US, and Canada). Thus the OECD figures actually underestimate how much of GDP is going to social spending in the world’s richest nations today.

Compared to the 20-30% of GDP that most OECD nations currently devote to health, education, social security, and the like, the 1 or 2% expenditures in Italy, the Netherlands, and England from the Renaissance through the 19th century look paltry indeed. But it’s important to remember that most people were living at subsistence levels until the end of the 19th century anyway. You can’t expect people, or their nations, to take an abiding interest in the welfare of strangers in need until they have enough surpluses of their own to meet their own needs and the needs of their loved ones.

My Kid’s Middle School Teacher Teams Up with Richard Dawkins to Start The Teacher Institute for Evolutionary Science (TIES)

Last night, I got a text message from my kid’s middle school science teacher, Bertha Vazquez. She’s a hell of a teacher, and she’s also a huge fan of Richard Dawkins–particularly because of how effective he is at making evolution make sense. Some time ago Bertha told me that she was working on a project with Richard to create a project designed to provide teachers with better tools for teaching evolution in the middle-school curriculum.

The project has now been launched! The mission of Teacher Institute for Evolutionary Science (TIES), a project of the Richard Dawkins Foundation for Reason and Science, is to teach “middle school science teachers the most-up-to-date concepts of evolutionary science.” They have plans for workshops, web-based tools, and the quantitative measurement of learning outcomes. It’s a brand-new endeavor, and you can read more here.

You can watch a video introduction of TIES here.

If you want to make a donation (which the Louis J. Appignani Foundation will match dollar-for-dollar through the rest of 2015), visit the TIES fund-raising site on RocketHub.

Is Kim Davis Really Wrestling with a Violated Religious Conscience?

AP_kim_davis_mm_150901_4x3_992-640x402

Kim Davis, you’ll surely recall, is the Kentucky Clerk of Courts who ended up spending five days in a jail cell after refusing to comply with a federal judge’s orders to sign marriage licenses for gay couples. She’s out now, and back at work, and so far has been allowing her deputy clerks to sign the licenses in her stead. So most of us were hoping we’d never hear about Kim Davis again.

But she’s back in the news. Upon returning to work, according to Brian Mason, one of her deputies, Davis confiscated all copies of the County’s standard marriage certificate and replaced them with the Kim Davis Custom Edition, which “deletes all mentions of the County, fills in one of the blanks that would otherwise be the County with the Court’s styling, deletes her name, deletes all of the deputy clerk references, and in place of deputy clerk types in the name of Brian Mason, and has him initial rather than sign.”

So the struggle continues. In an interview with ABC News that came out today, Davis tried to explain why signing a marriage license for a gay couple violates her religious conscience, and some of these statements are helpful in helping us to get into Davis’s mind:

“I can’t put my name on a license that doesn’t represent what God ordained marriage to be,” she told a reporter. “They’re not valid in God’s eyes.”

Sounds like a classic claim of a violated religious conscience, doesn’t it? Davis can’t participate in the duties that the State of Kentucky requires of her office, she says, because of a religious objection. Most bloggers are focusing on whether the law entitles Davis to accommodations, and whether such accommodations are possible without placing an undue burden on a class of people, but I have been thinking about a different issue:

Is it possible that Davis only thinks that signing a gay couple’s marriage certificate would violate her religious conscience? Is it possible that even Kim Davis doesn’t understand Kim Davis’s motivations?

If we’re not dealing with a violation of religious conscience, what else might we be dealing with? I see three possible alternatives.

Open-Hearted Ignorance? Why are Clerks of Courts required to sign marriage licenses in the first place? Best I can tell, the Clerk’s function in this setting is merely to aver that all relevant documents are in order (i.e., “I looked for everything; it’s all there.”). Now, I’ve never seen a Kentucky marriage license, so I may be wrong here, but I have seen a California marriage license (my own), and as far as I can tell, the clerk is merely certifying that all of the documents that are required to execute a legal marriage contract are on file, that there are no valid legal objections to the marriage on file, and that the credentials of the person officiating (“solemnizing”) the marriage are approved by the State. In other words, the Clerk’s signature is merely an assurance that the paperwork is right. This fits with my intuitions about what a Clerk of Court’s job is more generally: Opening envelopes, cashing the money order you sent in to pay for your traffic ticket, checking boxes, and not losing things.

I wonder if perhaps Davis simply hasn’t thought carefully enough about what her signature on a marriage license—any marriage license–actually means. She’s in pretty deep now, and has dug in her heels, so she probably cannot be reached with reason alone, but it seems like someone ought to try. Who knows? Perhaps with time, perspective, and some discussion with people who love her and whom she trusts, Davis could be convinced that her signature is really just a bit of truth-telling (“Yep!  Everything’s on file!), and thus is in fact extremely consistent with her Christian values rather than an affront to them.

Disgust Masquerading as a Violated Religious Conscience? Second, I wonder whether Davis might be confusing disgust with a violation of religious conscience. Legal scholars such as Martha Nussbaum, as well as many social scientists, have written on the centrality of disgust to people’s anti-gay prejudices, and the Kim Davis situation may provide an interesting and never-before-seen variation on this theme. If Davis is disgusted by gay people or by gay marriage, then she might be hesitant to associate her name with a gay couple’s marriage license because disgust follows the laws of sympathetic magic: The things associated with you carry some of your traits along with them. In the same way that people don’t want to drink from a glass that once held a cockroach, those who are extremely disgusted by homosexuality or homosexual marriage might be unwilling to associate themselves—or their signatures—with a marriage license—a piece of paper—that has been filed by two gay people. After all, the signature has been a highly cherished representation of the self, one’s will, and one’s intentions, for 3,500 years.

If Davis’s problem is in fact not that her religious conscience has been violated, but instead is that she is disgusted by the idea of gay marriage, then the religious language can be removed from the debate entirely and we can start discussing instead what society should do with an elected public official who finds part of her work disgusting.

Weaponized Conscience? Finally, there is the possibility that Davis isn’t experiencing a genuine violation of her religious conscience at all, but instead is simply using that plea as a cudgel that enables her to impose burdens on a class of people whose behavior she (or, perhaps, she believes, God) dislikes. By Davis’s own account, she believes God has been “using” her through this debacle (“For God to use somebody like me, it’s so humbling,” she has said). I’d certainly like for her to explain that statement. It could mean a lot of things, but one thing it could mean is that this entire dust-up, in her heart of hearts, isn’t actually about “U.S. versus God & Davis:” Instead, in Davis’s heart of hearts, it could be about “God versus the U.S. via Davis.”

Take a moment to let that one sink in.

No Truth Serum

None of us, save perhaps those people in Davis’s most intimate inner circle, are ever going to know what’s really going on in Davis’s heart. Is her conscience really, truly, legitimately violated? Is she absolutely sure? Could she be disabused of that intuition by taking a little time to think about what a Clerk of the Courts actually does (remember, their job is merely to open envelopes, cash checks, check boxes, and not lose things) and what the Clerk’s signature on a marriage license actually means? Is her perceived violation of religious conscience just a case of projected disgust dressed in its Sunday best? Or is her plea of violated religious conscience a disingenuous one—a rhetorical weapon that Davis is using to impose a burden on a class of people whose behavior she (or, she thinks, God) dislikes?

The last possibility is the most interesting—and the most troubling, actually, for it raises an ominous but delightfully “meta” sort of question about religious conscience. And it’s a question that defenders of religious liberty—both liberal and conservative—need to take seriously. Should one’s religious (or non-religious) conscience be bothered if someone has debased the very notion of religious conscience by using it as moral cover for a less conscionable goal? I’m not saying she has, and I’m not saying she hasn’t, because I do not know.

But I’d certainly like to know, because the liberal compact is something like this: “You’re free to believe what you want, and I’m going to defend that freedom on your behalf. But it seems to me that there’s a caveat: “If you’re just messing around and don’t actually believe what you claim to believe, then don’t count on me to make good on my side of the bargain either.”

h/t Deb Lieberman.

Cat-outside-box

Thinking Outside the Box: The Power of Apologies in Cooperative Agreements

TWO kids I know—let’s call them Jeff and Mimi–wanted a cat, so they begged their reluctant parents for months. Eventually the parents gave in, but they forced the kids into an agreement: “The cat box will need to be cleaned every day. We expect you to alternate days. If you miss your day, we’ll take fifty cents out of your allowance and give it to your sister/brother. If you like, you can think of the fifty-cent transfer as a ‘fine’ that we pay to your sister/brother for your failure to hold up your end of the agreement.” The kids agreed and Corbin the cat was purchased (or, rather, obtained from the Humane Society). The litter box-cleaning arrangement went well for three whole days, but compliance started to wane on day four. Hostilities began to simmer. Jeff became reluctant to clean the litter box on “his” days because of Mimi’s failures to keep up her end of the bargain, and vice versa.

“Recriminations” began to pile up.

After two weeks, the agreement was declared dead. The parents became the chief cleaners of the litter box. The father continues to wonder whether he should have read more game theory before even entertaining the idea of getting a cat.

Cooperative agreements like these tend to be dicey propositions: What’s Mimi supposed to do if Jeff fails to clean the box on his appointed day? Should he view it as a sign that Jeff no longer intends to honor the agreement (in which case she should stop honoring it herself, notwithstanding the $.50 fine that Jeff had to pay to her), or should she view it as a one-off aberration (in which case she might want to continue honoring the agreement)? It’s not clear, and that lack of clarity can make problems for the stability of such agreements.

Luis Martinez-Vaquero and his colleagues addressed this issue in a recent article that caught my eye. The paper is complex, but it’s full of interesting results (some quite counter-intuitive) about when strategic agents should be expected to make commitments, honor commitments, retaliate when those commitments are broken, and so forth. I suggest you give it a read if you are at all interested in these issues. But what really grabbed my interest was the authors’ exploration of the idea that the key to getting such agreements to “work” (by which I mean, “become evolutionarily stable*”) was to build in an apology-forgiveness system that causes agreement-violators to pay an additional cost (over and above the fine specified in the agreement itself) after a failure to cooperate, which might cause the defected-against partner to persist in the agreement despite the fact that it has been violated.

The researchers’ results enabled them to be surprisingly precise about the conditions under which highly cooperative strategies that used apologies and forgiveness in this way would evolve*: The costs of cooperating (cleaning the litter box) must be lower than the cost of the apology (the amount of money the deal-breaker voluntarily passes to his/her sibling), which in turn must be lower than the fine for non-compliance that is specified within the agreement itself (fifty cents). When those conditions are in place, you can get the evolution of actors who like to make agreements, accept agreements, honor agreements, and forgive breaches of agreements so that cooperation can be maintained even when those agreements are occasionally violated due to cello lessons that run late, or unscheduled trips to the emergency room, or geometry exams that simply must be studied for.

I’ve written here and there (and here) about the value of apologies and compensation in promoting forgiveness, but the results of Martinez-Vaquero and colleagues suggest (to me, anyway) that forgiveness-inducing gestures such as apologies and offers of compensation can come to possess a sort of fractal quality: People often overcome defections in their cooperative relationships through costly apologies, which promote forgiveness. Throughout the history of Western Civilization, various Leviathans have capitalized on the conflict-minimizing, cooperation-preserving power of costly apologies by institutionalizing these sorts of innovations within contracts and other commitment devices that specify fines and other sanctions if one party or the other fails to perform. But after the fine has been paid for failure to perform, what’s to keep the parties motivated to continue on with their agreement? Martinez-Vaquero et al.’s paper suggests that a little “apology payment” added on top of the fine might just do the trick. Apologies within apologies.

By the way, Jeff and Mimi’s parents are reviewing the terms of the old agreement later this week. Perhaps it can be made to work after all.

Reference:

Martinez-Vaquero, L. A., Han, T. A., Pereira, L. M., & Lennaerts, T. (2015). Apology and forgiveness evolve to resolve failures in cooperative agreements. Scientific Reports, 5: 10639.  doi:10.1038/srep10639.


 

*By which I mean “come to characterize the behavior of individuals in the population via a cultural learning mechanism that causes individuals to adopt the strategies of their most successful neighbors.”

 

Human Oxytocin Research Gets a Drubbing

There’s a new paper out by Gareth Leng and Mike Ludwig1 that bears the coy title “Intranasal Oxytocin: Myths and Delusions” (get the full text here before it disappears behind a pay wall) that you need to know about if you’re interested in research on the links between oxytocin and human behavior (as I am; see my previous blog entries here, here, and here). Allow me to summarize some highlights, peppered with some of my own (I hope not intemperate) inferences. Caution: There be numbers below, and some back-of-the-envelope arithmetic. If you want to avoid all that, just go to the final paragraph where I quote directly from Gareth and Mike’s summary.

brain-OTFig 1. It’s complicated.

  1. In the brain, it’s the hypothalamus that makes OT, but it’s the pituitary that stores and distributes it to the periphery. I think those two facts are pretty commonly known, but here’s a fact I didn’t know: At any given point in time, the human pituitary gland contains about 14 International Units (IU) of OT (which is about 28 micrograms). So when you read that a researcher has administered 18 or 24IU of oxytocin intranasally as part of a behavioral experiment, bear in mind that they have dumped more than an entire pituitary gland’s worth of OT into the body.
  2. To me, that seems like a lot of extra OT to be floating around out there without us knowing completely what its unintended effects might be. Most scientists who conduct behavioral work on OT with humans think and of course hope that this big payload of OT is benign, and to be clear, I know of no evidence that it is not benign. Even so, research on the use of OT for labor augmentation has found that labor can be stimulated with as little as 3.2 IU of intranasal OT during childbirth by virtue of its effects on the uterus. This is saying a lot about OT’s potential to influence the body’s peripheral tissues because that OT has to overcome the very high levels of oxytocinase (the enzyme that breaks up OT) that circulate during pregnancy. It of course bears repeating that behavioral scientists typically use 24 IU to study behavior, and 24 > 3.2.2
  3. Three decades ago, researchers found that rats that received injections of radiolabeled OT showed some uptake of the OT into regions of the brain that did not have much of a blood brain barrier, but in regions of the brain that did have a decent blood brain barrier, the concentrations were 30 times lower. Furthermore, there was no OT penetration deeper into the brain. Other researchers who have injected rats with subcutaneous doses of OT have managed to increase the rats’ plasma concentrations of OT to 500 times their baseline levels, but they found only threefold increases in the CSF levels. On the basis of these results and others, Leng and Ludwig speculate that as little as 0.002% of the peripherally administered OT is finding its way into the central nervous system, and it has not been proven that any of it is capable of reaching deep brain areas.
  4. The fact that very low levels of OT appear to make it into the central nervous system isn’t a problem in and of itself—if that OT reaches behaviorally interesting brain targets in concentrations that are high enough to produce behavioral effects. However, OT receptors in the brain are generally exposed to much higher levels of OT than are receptors in the periphery (where baseline levels generally range from 0 to 10 pg/ml). As a result, OT receptors in the brain need to be exposed to comparatively high amounts of OT to produce behavioral effects—sometimes as much as 5 to 100 nanograms.
  5. Can an intranasal dose of 24 IU deliver 5 – 100 nanograms of OT to behaviorally relevant brain areas? We can do a little arithmetic to arrive at a guess. The 24 IU that researchers use in intranasal administration studies on humans is equivalent to 48 micrograms, or 48,000 nanograms. Let’s assume (given Point 3 above) that only .002 percent of those 48,000 nanograms is going to get into the brain. If that assumption is OK, then we might expect that brain areas with lots of OT receptors could—as an upper limit—end up with no more than 48,000 nanograms * .00002 = .96 (~1) nanogram of OT. But if 5 – 100 nanograms is what’s needed to produce a behavioral effect, then it seems sensible to conclude that even a 24 IU bolus of OT (which, we must remember, is more than a pituitary gland’s worth of OT) administered peripherally is likely too little to produce enough brain activity to produce a behavioral change—assuming that it’s even able to get into deep brain regions.

Leng and Ludwig aren’t completely closed to the idea that intranasal oxytocin affects behavior via its effects on behaviorally relevant parts of the brain that use oxytocin, but they maintain a cautious stance. I can find no better way to summarize their position clearly than by quoting from their abstract:

The wish to believe in the effectiveness of intranasal oxytocin appears to be widespread, and needs to be guarded against with scepticism and rigor.


1If you don’t know who Gareth Leng and Mike Ludwig are, by the way, and are wondering whether their judgment is backed up by real expertise, by all means have a look at their bona fides.

2A little bet-hedging: I think I read somewhere that there is upregulated gene expression for oxytocin receptors late in pregnancy, so this could explain the uterus’s heightened sensitivity to OT toward the end of pregnancy. Thus, it could be that the uterus becomes so sensitive to OT not because 3.2 IU is “a lot of OT” in any absolute sense, but because the uterus is going out of its way to “sense” it. Either way, 3.2 IU is clearly a detectible amount to any tissue that really “wants”* to detect it.


*If you’re having a hard time with my use of agentic language to refer to the uterus, give this a scan.

 

What Does Revenge Want?

hellocopyIn The Princess Bride, the Spanish swashbuckler Inigo Montoya (played memorably by Mandy Patinkin), is the poster child for the seductive power of revenge. Montoya is a man whose entire adult life has been directed and shaped by his desire to avenge the death of his father. (The scene in which he ultimately fulfills this central goal of his life can be seen here in this YouTube clip. Only a few weeks ago did I realize that the other actor in this scene is the great Christopher Guest).

History provides us with other fascinating examples of the compelling power of the desire for revenge: Geronimo, the famous Apache warrior, describes his satisfaction after the slaughter of the Mexican forces that had massacred his mother, wife, and children only a year before: “Still covered in the blood of my enemies, still holding my conquering weapon, still hot with the joy of battle, victory, and vengeance, I was surrounded by the Apache braves and made war chief of all the Apaches. Then I gave orders for scalping the slain. I could not call back my loved ones, I could not bring back the dead Apaches, but I could rejoice in this revenge.[1] In Blood Revenge, the anthropologist Chris Boehm recounts how one of his informants described how a tribal Montenegrin typically feels after taking revenge against an enemy: “[H]e is happy; then it seems to him that he has been born again, and as a mother’s son he takes pride as though he had won a hundred duels.”[2]

Inigo Montoya, Geronimo, and tribal Montenegrins notwithstanding, the notion that revenge brings satisfaction does not sit easily with all psychologists. Kevin Carlsmith, Tim Wilson, and Dan Gilbert published a paper in 2008, for instance, that seemed to suggest that people only believed that revenge would bring satisfaction.[3] The notion that revenge was satisfying was, the authors suspected, another example of affective forecasting (an idea that I generally like, by the way): people only think that revenge is satisfying. They found that people did indeed expect to feel better after seeking revenge, but when given an actual opportunity to punish a bad guy after mistreatment in the lab, Carlsmith and colleagues found that avengers actually felt less satisfied than did victims who stayed their hands.

The Carlsmith et al. finding—people only think revenge will make them feel better, when it in fact makes them feel worse—has become a kind of psychological truism about revenge. Just yesterday, for example, this bit of common knowledge got repeated in an otherwise excellent article on revenge that appeared in the New York Times. In the article, Kate Murphy writes, “But the thing is, when people take it upon themselves to exact revenge, not only does it fail to prevent future harm but it also ultimately doesn’t make the avenger feel any better. While they may experience an initial intoxicating rush, research indicates that upon reflection, people feel far less satisfied after they take revenge than they imagined.”

But Murphy’s claim ignores a lot of data that indicates otherwise.[4] A series of experiments from Mario Gollwitzer and his colleagues have shown that people are in fact capable of experiencing just as much satisfaction from revenge as they were hoping for, especially when they become aware that the transgressor has learned a lesson from the punishment and has decided to mend his or her ways as a result of it. What revenge wants, it appears, is not simply to lob a grenade over a wall at a bad guy, or to blow off a little steam. Instead, what revenge wants is a reformed scoundrel—an offender who both realizes that what he or she has done to a victim was morally wrong and who acknowledges his or her intent to avoid harming the avenger again in the future. When revenge accomplishes these goals, it seems, it really does satisfy. The bad guy has been deterred from repeating his or her harmful actions. The goal has been accomplished. The itch has been scratched.

Let me be clear: Revenge is bad. It’s bad for relationships (generally), it’s bad for business, it’s bad for societies, and it’s bad for world peace. It’s probably even bad for your health. I’ve never met anybody who wanted more revenge in the world (except, of course, they were the wronged party). But no one has ever gotten rid of any bad thing in the world by understanding it less clearly. Ugly or not, revenge that finds its target can be as exhilarating as winning the Super Bowl. Once we really understand that revenge wants deterrence, we’ll be in a better position to create institutions that can provide alternative means of scratching the itch.

Boehm, C. (1987). Blood revenge: The enactment and management of conflict in Montenegro and other tribal societies (2nd ed.). Philadelphia: University of Pennsylvania Press.

Carlsmith, K. M., Wilson, T. D., & Gilbert, D. T. (2008). The paradoxical consequences of revenge. Journal of Personality and Social Psychology, 95, 1316-1324. doi: 10.1037/a0012165

Funk, F., McGeer, V., & Gollwitzer, M. (2014). Get the message: Punishment is satisfying if the transgressor responds to its communicative intent. Personality and Social Psychology Bulletin, 0146167214533130. doi: 10.1177/0146167214533130

Geronimo. (1983). Geronimo’s story of his life. New York: Irvington.

Gollwitzer, M., & Denzler, M. (2009). What makes revenge sweet: Seeing the offender suffer or delivering a message? Journal of Experimental Social Psychology, 45, 840-844. doi: 10.1016/j.jesp.2009.03.001

Gollwitzer, M., Meder, M., & Schmitt, M. (2011). What gives victims satisfaction when they seek revenge? European Journal of Social Psychology, 41, 364-374. doi: 10.1002/ejsp.782

[1] Geronimo (1983).

[2] Boehm (Boehm, 1987).

[3] Carlsmith, Wilson, and Gilbert (2008).

[4] Funk, McGeer, and Gollwitzer (2014); Gollwitzer and Denzler (2009); Gollwitzer, Meder, and Schmitt (2011).