Disruptive Mood Dysregulation Disorder: A Diagnosis for Tantrums?

The DSM-5 is generating a lot of controversy. I could write a lot of about my position on various aspects of DSM-5 - the changes to the autism spectrum, the callous-unemotional specifier, bereavement, and so forth. But in this post, I'll focus on Disruptive Mood Dysregulation Disorder (DMDD) and why I think this condition, despite the negative reaction it's gotten, is actually a good idea. (Though I still would like some changes to it.)

First, the criticism about this diagnosis seems to be predominantly about one thing - the perception of it as a 'tantrum diagnosis'. The fear is that this will be used to diagnose children with normal tantrums, giving a psychiatric diagnosis to something that doesn't really need one.

If you look at the proposed criteria, however, you can notice the following three things:

Age of Onset
A child under 6 is not allowed to get a DMDD diagnosis (nor is an adult over 18 - the idea is that DMDD normally turns into other things). In addition, first symptoms must be present before the age of 10. In other words, to meet criteria, the child has to be having tantrums at least three times a week between the ages of 6-10 years old. (Even if you were to diagnose a kid who is between 10 and 18 years old with DMDD, you have to prove they showed tantrums between 6-10 years.)

There are two main age periods where tantrums tend to be common in typically-developing children. The first age period is toddlerhood. Before about 3 or 4, many kids have tantrums on a daily basis, and even skilled parenting cannot prevent many tantrums. Specifically, one study found that 87% of 18-24 month olds and 91% of 30-36 month olds had tantrums, so there is definitely an age at which tantrums are normal. In fact, it's more likely that an 18-36 month old who never has tantrums would have a problem, although as far as I know no one has specifically examined those kids to find that out. However, by 42-48 months, this had dropped to 59%, and by the age of 6, tantrums are fairly uncommon.

The second age period at which tantrums are common is adolescence. Hostility between parent and child increases as children enter adolescence. Parent-child conflict tends to peak in early adolescence, although not as consistently as tantrums in toddlers. There is also evidence that this relates to physical pubertal development, with conflict tending to peak when the child is midway through puberty.

The age range delineated by the DMDD diagnosis, therefore, is an age where tantrums are less common in typical children. Most 6-10 year olds are between high-tantrum stages - they've outgrown toddlerhood and are not yet in puberty. A kid who tantrums frequently in that age range, therefore, is a lot more likely to be atypical in some way.

Developmentally Inappropriate
As an added safeguard against diagnosing normal tantrums, they include the sentence 'The temper outbursts are inconsistent with developmental level'. What this means is that diagnosticians need to take into account what would be expected in terms of tantrumming in that child.

There are two main groups who, at 6-10 years old, are likely to be having frequent developmentally appropriate tantrums - cognitively disabled kids and early developers.

In terms of cognitively disabled kids, a 6-10 year old who is at a 1-5 year old level cognitively and has frequent tantrums is not acting that unusual for his or her cognitive level. Given the research I already reviewed, even daily tantrums would be consistent with that child's cognitive level. Overall, it's probably going to be pretty tricky to diagnose DMDD in a child with significant cognitive impairment, although unusually severe tantrums (extremely long-lasting or associated with serious risk of physical harm) may be considered in excess of what their cognitive level would predict.

For early developers, if a child (especially a girl) has suddenly started having tantrums, and is towards the later end of that 6-10 year age range, it would make sense to consider puberty as an alternate explanation. The cutoff for clinical definition of precocious puberty is currently 8 years for girls and 9 for boys, although some research suggests we should be lowering the cutoff. Therefore, although most 6-10 year olds are prepubertal, there will be some who are not. Tantrums in child who is entering puberty are developmentally expected.

Irritability
Lastly and most importantly, although everyone has focused in on the tantrum-related criteria, a child who has frequent developmentally inappropriate tantrums without any other behavioral or mood issues will not actually meet criteria for DMDD, because DMDD is more than just tantrums. Take a look at this:

"C. Mood between temper outbursts: 
1. Nearly every day, most of the day, the mood between temper outbursts is persistently irritable or 
angry.
2. The irritable or angry mood is observable by others (e.g., parents, teachers, peers)."

So, a DMDD child is not just a kid who throws tantrums. Even when he or she is not pitching a fit, the child acts grumpy or angry most of the time. Even without the tantrums, this persistent irritability could be a cause for concern by itself.

Persistent irritability, by the way, is not typical for any developmental stage. Toddlers are not persistently irritable - instead, they tend to have rapidly changing moods, including both ups and downs. Teenagers are also not persistently irritable. Though the more rebellious teens may be irritable whenever interacting with adults, they don't act that way with their peers, or when doing an activity they enjoy. A persistently irritable kid won't find much to enjoy in life.

Incidentally, this criteria is the main reason this condition is considered a mood disorder. Tantrums, by themselves, are externalizing behavior, and developmentally abnormal tantrums are seen in most externalizing disorders (ADHD, ODD, CD, etc). But persistent irritability is a mood problem. In DSM-IV, irritable mood is listed as a characteristic of depression in children. (I couldn't find information on whether they are removing this criterion in DSM-5. Anyone know?)

And now, on to my criticisms of DMDD.

Unclear Criteria
Both tantrums and irritability are described in very sparse terms, leaving a lot to the clinician's judgment.

Apart from describing verbal and/or physical aggression, they say almost nothing about what defines a tantrum. How long does the behavior have to be ongoing to be considered a tantrum? If the tantrums is interrupted by some non-tantrumming behavior (such as going to the bathroom), is it one tantrum or two? If the kid has been throwing a fit on and off about one topic for several days, is that a 3-day long tantrum, or 6 different tantrums within a 3 day period? Does a single act of aggression within a bout of crying make it count as a tantrum, or does angry behavior have to be more prominent than distressed behavior in a tantrum episode?

Similarly, what is irritability? Is it a baseline unpleasant mood, or is it overreacting to minor triggers? What specific behaviors are signs of irritability? How do you distinguish a persistently irritable child from a persistently depressed or anxious child? How long does the kid need to have been irritable before it counts for diagnosis? If he started feeling irritable two weeks before he saw the doctor, does that count?

For most DSM diagnoses, they unpack this a lot more. Hopefully, they will start to do so with DMDD, otherwise I could see a lot of individual clinicians disagreeing about diagnosis.

Irritability Alone
What if you have a kid who is irritable most or all of the time, but who either doesn't have tantrums, or averages fewer than three tantrums a week? That kid is clearly in distress and needs help, but what condition does he or she have?

According to the suggested criteria, that kid doesn't have DMDD. Does he or she have depression or dysthymia? Possibly, but what if the kid's energy level is fine, he or she is eating and sleeping well, and instead of feeling guilty or worthless, he or she is feeling angry and resentful?

I could see these kids slipping through the cracks. There needs to be more research - maybe it so happens that kids who are persistently irritable always have tantrums at least three times a week, or maybe kids who are irritable without tantrums have very little in common with kids with both issues, but we just don't know. And if there are persistently irritable kids, who are not depressed and don't have regular tantrums, what do we diagnose them with?

Conclusion
On the balance of things, I think adding DMDD is a good idea. Well before DSM-5 was announced, I'd wondered why the DSM had diagnoses focused on problematic fear and sadness, but nothing directly related to problematic anger. (Just diagnoses about behavior that could result from anger, but might not.) And I'd read research suggesting that there was a category of kids whose main issue was irritability and anger.

It bothers me that most of the people who criticize changes in the DSM-5 have no idea of the research that goes behind those changes. For example, 'aspies' who insist that Asperger Syndrome is distinct from autism, ignoring all the research showing that the two cannot be reliably distinguished. (Best I can tell, most of them want to feel special by distancing themselves from the stigma of autism.) Or the people complaining about DSM-5 allowing depression diagnosis in recently bereaved individuals, who seem to have no knowledge of the research showing that recently bereaved people who meet depression criteria have the same sorts of problems and outcomes as people whose depression was triggered by other stressors or came out of the blue.

In the case of DMDD, the predominant criticism seems to be of a familiar tone. 'This psychiatric disorder vaguely resembles a pattern of normal behavior, so it must be the same as that normal behavior.' The reality is that virtually all psychiatric conditions have elements that, in much milder degrees, is present in most people. Everyone gets sad now and then, only some people get clinically depressed. Most people are shy at times, only a few have social anxiety disorder. Most people feel upbeat and energetic some of the time, but only a few actually become manic. Even some delusions have shadows in normal behavior - paranoia is an exaggeration of normal distrust of others, grandiosity is an exaggeration of normal self-enhancement, and so forth. Just because some people are dumb doesn't mean that someone with an IQ of 50 is normal. The degree to which you show a characteristic matters.

Recently I had someone ask me if you can have both Schizotypal Personality and an autism spectrum condition. I've gotten permission to repost my reply here. According to the person who asked me the question, my reply was quite helpful.

I think it probably is possible to be both schizotypal and AS, although it would be tricky to determine because some of the symptoms overlap. Both conditions have odd mannerisms, poor social skills and probably executive dysfunction (don't know if EFD has been observed in schizotypal, but it's definitely present in schizophrenia, which is a related but more severe condition). I suspect that sensory sensitivities are common in schizotypal as well. The way to tell if someone has both would be to look for the symptoms that aren't shared between the two conditions. 

Look at the DSM-IV criteria for schizotypal and for autism: 

Schizotypal Personality: 

A. A pervasive pattern of social and interpersonal deficits marked by acute discomfort with, and reduced capacity for, close relationships as well as by cognitive or perceptual distortions and eccentricities of behavior, beginning by early adulthood and present in a variety of contexts, as indicated by five (or more) of the following: 

(1) ideas of reference (excluding delusions of reference) 

(2) odd beliefs or magical thinking that influences behavior and is inconsistent with subcultural norms (e.g., superstitiousness, belief in clairvoyance, telepathy, or "sixth sense"; in children and adolescents, bizarre fantasies or preoccupations) 

(3) unusual perceptual experiences, including bodily illusions 

(4) odd thinking and speech (e.g., vague, circumstantial, metaphorical, overelaborate, or stereotyped) 

(5) suspiciousness or paranoid ideation 

(6) inappropriate or constricted affect 

(7) behavior or appearance that is odd, eccentric, or peculiar 

(8) lack of close friends or confidants other than first-degree relatives 

(9) excessive social anxiety that does not diminish with familiarity and tends to be associated with paranoid fears rather than negative judgments about self 

Autism (DSM-IV Asperger Syndrome requires only A and C): 

(I) A total of six (or more) items from (A), (B), and (C), with at least two from (A), and one each from (B) and (C) 

(A) qualitative impairment in social interaction, as manifested by at least two of the following: 

1. marked impairments in the use of multiple nonverbal behaviors such as eye-to-eye gaze, facial expression, body posture, and gestures to regulate social interaction 

2. failure to develop peer relationships appropriate to developmental level 

3. a lack of spontaneous seeking to share enjoyment, interests, or achievements with other people, (e.g., by a lack of showing, bringing, or pointing out objects of interest to other people) 

4. lack of social or emotional reciprocity ( note: in the description, it gives the following as examples: not actively participating in simple social play or games, preferring solitary activities, or involving others in activities only as tools or "mechanical" aids ) 

(B) qualitative impairments in communication as manifested by at least one of the following: 

1. delay in, or total lack of, the development of spoken language (not accompanied by an attempt to compensate through alternative modes of communication such as gesture or mime) 

2. in individuals with adequate speech, marked impairment in the ability to initiate or sustain a conversation with others 

3. stereotyped and repetitive use of language or idiosyncratic language 

4. lack of varied, spontaneous make-believe play or social imitative play appropriate to developmental level 

(C) restricted repetitive and stereotyped patterns of behavior, interests and activities, as manifested by at least two of the following: 

1. encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity or focus 

2. apparently inflexible adherence to specific, nonfunctional routines or rituals 

3. stereotyped and repetitive motor mannerisms (e.g hand or finger flapping or twisting, or complex whole-body movements) 

4. persistent preoccupation with parts of objects 

So, if you look at those two, the following overlaps are present: 

* schizotypal criteria 3 overlaps with autism B3 and B2 (verbal communication issues and odd language use) 

* schizotypal criteria 6 is the same as autism A1 (impairment in expressive use of nonverbal cues) 

* schizotypal criteria 7 can result from autism A1 and C3 

* schizotypal criteria 8 is a more severe form of autism A2 (you can meet A2 and have friends if your friendships are atypical or you have a lot of trouble making friends, but if you don't have any friends you meet both 8 and A2) 

In addition, I've often seen schizotypal 9 and possibly 5 in AS people as a result of bullying. A lot of AS people are too trusting, but if they get hurt too much by others, they can switch to not trusting enough. 

Now, schizotypal is not supposed to be diagnosed if it occurs 'during the course of a pervasive developmental disorder' (which is outdated language given that we now know autism spectrum conditions are not episodic, like schizophrenia or bipolar disorder are). That probably means that you can't diagnose a person as schizotypal if an autism spectrum condition could explain all their schizotypal traits. 

So, that would probably mean that you don't count 6 or 8, and only count 3 and 7 if they are not due to autistic traits (eg if the language problems are more typical of thought disorder than autism, and the eccentric appearance is not due to stimming and/or odd nonverbal communication). Criteria 1, 2 and 3 could be counted, because those have nothing to do with autism, and criteria 5 and 9 could be counted as long as they're in more extreme than would be expected based on the person's history of negative social experiences. That could add up to the required five, but it would be harder to meet criteria than if you didn't have AS.

Also keep in mind that each clinician kind of interprets the rules differently. The existence of AS as a diagnosis is proof of this, because AS is supposed to be diagnosed only if autism criteria aren't met (ie, they meet A and C but not B), and some of the criteria in A and B are actually different ways of describing the exact same thing (eg A3 or A4 will cause B2, because you can't have that kind of social impairment and not have it affect your conversations with others). So research has shown almost everyone who meets criteria A actually meets B as well, but if the person had no language delay or fits the clinician's stereotype of AS in some way, they will ignore the B criteria and diagnose AS instead of autism. (Autism does require delay in social, communication or pretend play, but anyone who meets criteria A has a delay in social skills by definition.) So it's possible that if you were seen by a different clinician, you could have gotten a different diagnosis. Maybe another clinician would diagnose you as Schizotypal and AS, or decide Schizotypal fits you better than AS does. There's a certain amount of subjectivity to it.

Little Monsters

A few weeks ago at church, something happened that I found kind of upsetting.

Firstly, since I'm an atheist with bad experiences with religion, I go to church to support my parents and have contact with my community. I always wait downstairs until services are over, then chat with people afterwards.

Children who attend church also tend to hang out downstairs, because their need for activity and noise is less disruptive (though they still need to keep noise down so they can't be heard upstairs). Sometimes we have Sunday School activities for them, other times they just play freely. Sometimes no children show up at all (most of the congregation is over 65).

This particular time, there were three boys, two brothers and a cousin. One was 6, one was 5 and one was 4. I was quite enjoying watching them play hide-and-seek, because I'd noticed an intriguing difference between how the oldest boy played and how the younger two did. The younger two always hid in the same spot, and found it hard to avoid giggling as the older boy came looking. But when one of the younger boys was 'it', the older one would hide in a different spot, and would stay quiet. He also picked better hiding spots. This fascinated me because I'd just finished writing a paper that touched on theory of mind development, and I was speculating on what cognitive milestones affected hide-and-seek skill.

Then came the end of church. Relieved that they no longer had to make an effort to be quiet, the three boys began running in circles while shrieking, while the congregation drank coffee and chatted. I was talking to a couple of my friends in the congregation, trying to share my thoughts on child development, which didn't seem to be very interesting to them. Meanwhile, the noise was interfering with my ability to listen to their replies, and I was getting overloaded.

And then I made the mistake of commenting on this - saying that though I liked kids, I sometimes found the noise they made hurt my head. The guy I was talking to replied sympathetically, calling the kids 'little monsters'.

I was taken aback. Did he think I'd agree with that phrase, just because their sounds hurt my head? Had he failed to notice how happy I was, despite my overload, about the fact that these children were playing and enjoying themselves?

And this got me thinking. Why is it that our society is so negative towards children? Why is it considered permissible to make derogatory comments about children, simply because they need to move and make noise?

I get this kind of thing a lot. I have hypersensitive hearing, so I often find noise overloading. But when I make the mistake of identifying a child's noise as a source of overload, people assume I'm OK with anti-child statements.

The truth is, I love kids! I feel a sense of joy when I see a happy child. I find it really fun to play with a kid, or even just watch them play. Sure, when the noise level gets too high it starts to hurt, but if it's happy noises, that pain is tempered by happiness that the kid is happy.

Exposition Needs to Fit the Character

One of my pet peeves, in a lot of sci fi or fantasy stories, is when characters exposit about information in a way that doesn't fit their characterization. Specifically, when they know more than they should.

A lot of people might think it's a given - if you're personally affected by something, you'll want to understand it. People like that would be surprised to hear that I know more about cerebral palsy (in terms of scientific knowledge) than my best friend who has that condition. She's a smart person, a university student who gets decent marks, but it's me, not her, who can name the part of the brain that is usually affected in CP, can describe the differences between CP subtypes, and can list many potential causes of CP. Of course, she knows way more than I do about how it feels to move with CP, and what it's like to grow up using a wheelchair, and so forth, but when it comes to the science of the condition, having CP doesn't guarantee knowledge about it. The same is true of superpowers (and other supernatural or science fictiony conditions, but I'll focus on superpowers here.)

A far better predictor of whether you'll know about a condition is whether you have experience with the relevant scientific field. Bruce Banner obviously will know a lot about gamma radiation, given that it was his job before he started turning into the Hulk. Even Spiderman, who in most versions of the story was some form of student learning about the scientific field (which varies between continuities) that resulted in the mutation-inducing spider, has a pretty good reason to be knowledgeable about it. Similarly, in real life, an medical doctor who get sick will (unless their condition causes enough cognitive impairment to obliterate the benefit of their training) be pretty knowledgeable about what's happening to them. Similarly, an audiologist who develops hearing problems will be well-equipped to understand what's wrong and how to treat it.

Now, just because they weren't an expert in the area before it affected them does not mean they can't become an expert afterwards, and being personally affected can provide a significant motive to learn about something. But not everyone who is personally affected by something becomes knowledgeable about it, for three reasons:

Ability

Obviously, a smarter person is more able to absorb information than a dumber person. Most people can readily see that someone with Down Syndrome is unlikely to be able to explain what a trisomy is or how nondisjunction works. Even someone with an IQ in the lower end of average might struggle with highly technical concepts like that.

In addition, because of skill scatter, someone who is highly capable in one area may not be very capable in another. A gifted linguist could nevertheless lack the mathematical ability needed to explain particle physics, for example. Therefore, they may not be capable of understanding how their ability to shapeshift depends on manipulating the strong nuclear force.

This usually isn't too hard for writers to get, so I won't dwell on it too much, but I have seen a few gaffes of this type.

Motivation

This is the main reason why a person affected by the condition is more likely than a randomly selected person to be knowledgeable about the science behind this condition. But having a condition doesn't necessarily mean you want to learn about it.

For one thing, people cope with life-changing events in different ways. Some people decide to seek scientific knowledge when they acquire a medical condition. Others decide to talk to God, or philosophize about the meaning of life. Some decide they're going to focus on other things, like their family or their work. And some actively deny and avoid information, and try to pretend it isn't happening.

And that's with an acquired condition. If it has always been part of their life, it may never be a big enough deal to bother researching it. (Not everyone researches things for fun, like I do.) They may have learnt what they need to know at a very young age, and not feel a big need to learn more. They're much less likely than people with acquired conditions to invest a great deal of emotion (in any form) into their condition. Someone like that either needs to enjoy this kind of knowledge for its own sake, or to have some pressing motivation (besides just having the condition) to seek out information about it.

Therefore, the character who 'just wants to lead a normal life' is probably not going to be very knowledgeable about their superpowers. Neither will the one who cares more about being a superhero than learning about science. The one who is scared about adverse effects of their powers could go in either direction - either 'head in the sand' or learning as much as possible. The one who has always had powers will have had much more opportunity to learn about those powers, but also less interest in them than someone who's just gained them.

Interest also impacts what kind of information they gain. Imagine a family of hereditary shapeshifters - the shapeshifter with an interest in genetics might learn about how this characteristic is inherited, meanwhile the one with an interest in physics puzzles over where the extra matter goes when a 160 pound human becomes a 90 pound wolf. And the one interested in physiology examines how the body knows how to transform a plantigrade foot into a digitigrade foot, while his psychologist brother examines the emotional triggers that set off an uncontrolled transformation. (OK, now I want to write this family. This would make a neat story.)

Opportunity

Even if you are capable of understanding information, and are motivated to seek it out, you still have to actually find it. If the information you want doesn't actually exist, then unless you can discover it yourself, you won't know it. If you're a brand new kind of vampire, you won't know what your weaknesses are unless you encounter them and survive. If your child has just been diagnosed with a new syndrome that has been described in only one other journal article describing 3 patients, the oldest of which was 10 years old, you won't know if your kid has a 95% chance of developing cancer in his thirties.

And even if the information is known by someone, doesn't mean you can find it. Especially in stories where there's a Masquerade in place - a guy who was bitten by a werewolf he never saw again, in a setting where the existence of werewolves is a closely kept secret, will have a lot of trouble getting information about the condition. Even if the information isn't deliberately kept secret, you may not know what some tribespeople across the world from you consider common knowledge. Or maybe someone knew something, but that information has since been forgotten. If you're the first X in five thousand years, it could be tricky to figure out what the ancients knew.

Furthermore, the information could be wrong, either deliberately or unintentionally. Maybe a page from that ancient manuscript was torn out, or the author was unaware of something. Maybe the information is out of date, and new knowledge would change the situation. A great example is in one episode of Buffy the Vampire Slayer, where they face an ancient evil that was sealed away and is now being released. The information they can find on this creature indicates that no weapon created by humans can harm him, but Buffy and friends realize this was written prior to the development of modern weaponry, and kill the villain with a rocket launcher.

Opportunity also refers to your opportunity to gain the necessary prerequisite knowledge and cultural worldview. The book The Spirit Catches You and You Fall Down is a nonfiction story of a Hmong refugee family with a daughter with a severe form of epilepsy. A language barrier combined with significant differences in cultural worldview resulted in very little of the doctors' knowledge of epilepsy being communicated to the parents. This contributed to the girl's progressive deterioration, because her parents did not understand enough of Western medicine to give her effective treatment. For example, they did not know the difference between seizure medications and antibiotics, and did not realize they needed to refill her prescription when it ran out. Both linguistic and cultural barriers can come into play.

In fiction, one specific group for whom culture needs to be taken more into account are long-lived characters, such as vampires. Even if the vampire is adept at blending into human society, the impact of growing up in Medieval France in the 1300s will never completely disappear. It will shape their beliefs and way of thinking, and will have an impact on how they understand vampirism. For characters who were sealed away or otherwise unable to benefit from continuous experience with a changing society, the impact of their time period of origin will be felt even more strongly.

Conclusion

Don't be afraid to leave out some exposition if it doesn't fit in the mouths of any of your characters, or hint at it indirectly. If you absolutely must communicate it somehow, you can always try some non-canon medium such as an appendix at the end. You can tell your audience what they need to know for the plot without getting into all the science behind it. If your superhero just knows they can fly and turn invisible without having a clue how it works, that's fine. Even if you know how their powers work, they don't need to.

And don't be afraid to have your character be wrong about the facts. Even if they never learn any different. If it fits your story for them to be mistaken or uninformed, go ahead and write them that way. Just because a character claims something works a certain way doesn't have to mean they're right about it.

Don't use exposition solely to tell your audience how something works. Tell them something about the character, too. If one person calls vampirism a virus and the other calls it a (literal) curse, that tells you something about how they see the world. And if the 'dumb jock' suddenly explains how magic is the ability to violate the 'matter cannot be created or destroyed' principle, that should tell you about hidden depths in that character, and not just the author's determination to get that information across to the audience.

Emotions and the Dark Side

My brother just introduced me to an online game called Star Wars: The Old Republic. It's a fun game, set in a neat world, but playing it has reminded me of one thing that bugs me about the Star Wars universe.

Firstly, this is an old obsessive interest. When the first Star Wars movie came out (by first I mean in-story timeline, not first to be released - I'm referring to the one where they meet Anakin), I became obsessively interested in that setting, and fantasized about having the ability to control the Force (basically that universe's word for magic).

But even back then, the distinction between Jedi (good guy Force wielders) and Sith (bad guy Force wielders) bothered me. See, according to the lore, Jedi gain power by avoiding strong emotions - seeking out calm and serenity - whereas Sith gain power by feeding their emotions, amplifying them. Even back then, I figured they had it backwards.

See, I was always a deeply moral person, even as a small child. And my moral sense didn't come from cold rationality. Although I've always tried to reason things out to inform my moral decisions, morality is a deeply emotional thing for me. I get upset when I see injustice. I get sad when I see someone suffering. I feel good when I know I've done the right thing - even if it wasn't in my own self-interest. So the idea that emotions are associated with 'the Dark Side' and being unemotional is linked with 'the Light Side' never made sense to me.

Well, turns out my instinct was right. Morality is an emotional thing by nature. I'm not sure if 'evil' as a concept makes sense or is useful, so I'll talk about amoral people instead of evil people (amoral meaning someone whose behavior is not influenced by concerns about right and wrong). In psychology, amoral people are referred to as psychopaths. A number of studies have examined emotional experience in psychopaths and non-psychopaths (see this study for an example) and the most common conclusion is that, in certain specific ways, psychopaths are less emotional than non-psychopaths.

Now, granted, not all emotions are reduced in psychopaths. One emotion that psychopaths feel just as strongly as non-psychopaths is anger - the same emotion that is most commonly referred to in Star Wars as being felt by the Sith. A lot of people, myself included, tend to associate anger with evil. I get scared when people are angry, because an irrational, trauma-affected part of me insists that anger is bad and dangerous and will result in me getting hurt.

But anger is not really an evil emotion. If misdirected, it can cause harm to others, but so can sadness (eg murder-suicide) and fear (eg misdirected self-defense), and we don't tar those emotions with the 'evil' brush. And I've seen my mother and father get angry for good reasons, and direct their anger to accomplishing good things. For example, my father gets angry when people normalize rapists by suggesting that all men have trouble controlling their sexual behavior. (One example was the gang rape of a Cree 12 year old by three adult men who claimed their behavior was excusable because she, while drunk on booze they'd fed her, climbed on the one guy's lap and kissed him. That case got both of my parents angry.) My mother once got so angry at my school for mistreating me that she kicked a hole in the wall while she was on the phone with them.

The most important determinant of how important morality will be to you appears to be how strongly you react, emotionally, to suffering in others. So if generalized tendency to feel emotions has any relationship to morality, it's in the opposite direction from Star Wars lore.

The funny thing is, people know this. A lot of research in morality has focused on dilemmas such as the 'runaway train' model (explained here). These dilemmas pit the good of one or a few people against the good of many. In one version, both the few/one and the many are equally distant (people standing on train tracks while you're at the control booth deciding where the train will go. In that situation, it's easy to decide to redirect the train down the track containing fewer people. But when, instead, the sacrifice involves physically shoving a fat guy in the way of the train, people are more hesitant. Some refuse to say they'd shove the fat guy, even though it means five others dying. Others reluctantly settle on shoving the fat guy as the morally correct, though distasteful, option. However they decide, they feel unpleasant emotions about that situation.

So what if someone else calmly and easily decides to shove the fat guy off? According to this study, deciding too easily to take the utilitarian option, or taking the utilitarian option when the cost is highly salient to the person, results in harsher moral judgement. The reason? It implies that the person isn't deciding for the right reasons - they're not feeling the right emotion. Similarly, children recognize the importance of feeling remorse  after doing wrong, since expression of remorse had the strongest impact on their moral judgements of an actor.

I don't know where we got the idea that morality is rational and evil is emotional. Maybe it comes from our desire to convince ourselves that we're better than animals, since animals are as emotional as us but a lot less rational. But the facts show that feeling the right feelings, and feeling them strongly, is essential for morality. You can be great at thinking rationally, but if you don't feel unhappy at another person's misfortune, you won't be a moral person.