The Ph.D. Grind

I recently read Philip Guo’s memoir, The PhD Grind, detailing his experience working toward a PhD in Computer Science at Stanford. Even though elements of his experience were  unique and wouldn’t apply to many people doing PhDs in other fields, or even in computer science (and he acknowledges this fact), it was still incredibly interesting.

One real strength of this book is that Guo wrote it immediately after finishing his Ph.D., and argues that this was the best time to do so because current Ph.D. students aren’t able to reflect on the entirety of their experience, while people who completed their degrees years ago might have “selective hindsight.” Guo also details the good and the bad, unlike bitter PhD dropouts who dwell on the futility of working on a doctoral degree or successful researchers who extoll the wonderful journey that earning a Ph.D. entails.


An example of a less-than-triumphant time:

At the time, I had absolutely no idea that my first year of Ph.D. would be the most demoralizing and emotionally distressing period of my life thus far.

Another quote that really hit home for me:

I found it almost impossible to shut off my brain and relax in the evenings, which I later discovered was a common ailment afflicting Ph.D. students.

And, during a 10-week period of stagnation in which he hardly spoke to anyone:

There was no point in complaining, since nobody could understand what I was going through at the time. My friends who were not in Ph.D. programs thought that I was merely “in school” and taking classes like a regular student. And the few friends I had made in my department were equally depressed with their own first-year Ph.D. struggles – most notably, the shock of being thrown head-first into challenging, open-ended research problems without the power to affect the high-level direction of their assigned projects.

Related, and a difficulty I’ve already begun encountering:

Unlike our peers with regular nine-to-five jobs, there was no immediate pressure for grad students to produce anything tangible – no short-term deadlines to meet or middle managers to please.

I like this one too:

Contrary to romanticized notions of a lone scholar sitting outside sipping a latte and doodling on blank sheets of notebook paper, real research is never done in a vacuum.


A blunt but honest comment from the epilogue:

There simply aren’t enough available faculty positions, so most Ph.D. students are directly training for a job that they will never get.

But luckily, that thought is followed shortly after by this one:

So why would anyone spend six or more years doing a Ph.D. when they aren’t going to become professors? Everyone has different motivations, but one possible answer is that a PhD program provides a safe environment for certain types of people to push themselves far beyong their mental limits and then emerge stronger as a result… Here is an imperfect analogy: Why would anyone spend years training to excel in a sport such as the Ironman Triathalon – a grueling race consisting of a 2.4-mile swim, 112-mile bike ride, and a 26.2-mile run – when they aren’t going to become professional athletes? In short, this experience pushes people far beyond their physical limits and enables them to emerge stronger as a result. In some ways, doing a Ph.D. is the intellectual equivalent of intense athletic training.

Overall, Guo’s memoir recounts many more struggles that triumphs, but in the end, he still accomplished what he set out to do and claims to have made tremendous gains in the process. Maybe I’m in denial (thinking, “oh, but he was in Computer Science, so that won’t happen to me”), but I didn’t finish the book discouraged. Instead, I think I finished with some realistic expectations and even more determination that while an Ironman Triathalon may never be in the cards for me, I’m up for the challenge of the “Ph.D. grind.”


Metaphors We Live By

I recently read Metaphors we Live by, a seminal work in the field of metaphor research. Written by George Lakoff, a linguist, and Mark Johnson, a philosopher, the book incorporates both fields in an argument for metaphor’s importance in our lives. The authors make the case that metaphor allows us to apply our physical and social experiences to make sense of many other subjects. By this definition, metaphors structure our understandings of so many concepts in our lives (from arguments to time perception), and consequently shape our perceptions of and actions regarding those concepts.
While I do subscribe to their thesis, the most what struck me most when reading this work that I have so often read about was the observation that they were talking about embodiment without referring to it as such (probably because the term wasn’t yet in use). In a way, it seems to me, Lakoff and Johnson are hipsters, advocating for embodied cognition before it became trendy.
One example of this is their recurrent discussion of the general metaphor “happy is up,” (as are “good” and “healthy” – and their opposites are down). This is evident in metaphors like:
  • I’m down in the dumps
  • That speech was uplifting
  • Cheer up
  • My spirits rose
Down in the dumps, literally and metaphorically. Image:
Down in the dumps, literally and metaphorically.
Crucially, they argue, metaphors are systematic, not arbitrary. So if happy is up, we could never introduce a new metaphor into our language in which something like “he dropped down a level” meant that he got better in any way. Embodiment comes in when we realize that when we’re healthy and happy, we physically stand taller. We hold our heads higher and we look UP. Because in our personal experiences, “good” and “up” really do correlate, our metaphors reflect that. Then the metaphor becomes a self-fulfilling prophesy, as our subsequent actions may also be shaped by the metaphors which are first based in experience.
I think that if Lakoff and Johnson, or any of us, want to make the argument that our linguistic practice of equating “good” and “up” is rooted in our physiology, we should look at other languages. Do speakers of other languages have the same systematic metaphors? The presence of metaphors in which “down” and “good” are equated in any language would make me rethink this argument. They write that “not all cultures give the priorities we do to up-down orientation. There are cultures where balance or centrality plays a much more important role than it does in our culture” (p.24). I was eager to read elaboration on this, and maybe some examples… but that was all they wrote.Thus, for now, I’m on board with the idea that our bodies have systematically shaped our metaphors.
Some other interesting tidbits:
  • In addition to “up is good,” we also systematically express the unknown as up (i.e., that’s up in the air; I’d like to raise some questions; let’s bring it up for discussion). When we ask questions, presumably regarding something that’s  unknown to us, our intonation rises – not a coincidence, the authors claim.
  • The authors bring up the idea that in language (not just English), more form equals more content. So when we say “he is very very very tall,” we get the impression of a much taller man than one described as, “he is very tall.” Many languages use reduplication, the repetition of one or two syllables, to evoke more content as well. In some languages, reduplication applied to a singular noun makes it plural, or applied to a verb makes it continuous. These practices demonstrate another metaphor we live by – that a linguistic expression is a container and its meaning is the contents of that container. By adding more language to the container (expression), we add more content.
Some parts of the book were a little tough to get through (for me, that would be the philosophical parts), but overall my experience of reading the book was one dotted with a number of hm-I-never-thought-of-that moments. As a tribute to the importance of metaphor, I’ll close with the final paragraph of the afterword, an apt summary of the whole work:
 But metaphors are not merely things to be seen beyond. In fact, one can see beyond them only by using other metaphors. It is as though the ability to comprehend experience through metaphor were a sense, like seeing or touching or hearing, with metaphors providing the only ways to perceive and experience much of the world. Metaphor is as much a part of our functioning as our sense of touch, and as precious.

The Trolley Problem

For the first time in my life, I read an entire book dealing with ethics. And loved it! Tom Cathcart’s The Trolley Problem approaches a famous thought experiment in which a trolley is headed toward 5 people on the track (with the assumption that they will all die if the trolley continues), and a bystander has the opportunity to pull a switch, sending the trolley onto an alternative path where there is only one person who will be killed. Most people agree that pulling the switch is ethical, since five lives are saved, despite the one lost. Many alternate versions of the trolley problem have been devised over time to make different philosophical arguments about ethics and morality. In one version, for example, the trolley is still heading for the 5 innocent people, but a man on a bridge above realizes that if he could throw something heavy in front of the train, it will stop and the five lives will be spared. So he throws a heavyset man, again sacrificing one life to save 5. In this version, the idea that one death is better than five no longer seems to rationalize the person’s action. The trolley problem demonstrates that human ethics are far from clear-cut.

trolley book

In the book, Cathcart makes a thought experiment out of the thought experiment by writing as if the original trolley scenario actually did occur, and Daphne Jones, the woman who pulled the lever and caused the trolley to kill only one person, is on trial for murder. Many different angles are presented, including the prosecutor, defense, a number of professors in various fields, a bishop, a psychologist, and people who call in to express their views on NPR.

Each view is cleverly written, and as one of the jurors admits, regarding the arguments brought up earlier in the book, “After each one of you has spoken, I’ve found myself agreeing with you. Your arguments are all very persuasive – until I hear the next one.” I couldn’t agree with her more.

In the epilogue, Cathcart asks whether we’re any wiser, after hearing arguments for both sides of Daphne’s case. I can only speak for myself, but I feel wiser. This work continually forces the reader to reconsider what seems like a cogent argument, to question intuition, common sense, and rationality. If these faculties are fallible in this fictive case, can we trust them in our real lives?

The section that expressed a professor’s lecture in a class, “Critical Thinking in Contemporary Life,” really struck a chord with me because the subject of the lecture was analogies. She taught that analogies usually compare two people or things without expressing what about them is similar. And while they’re similar, they’re not actually the same, or it would make for a lousy analogy. In the context of Daphne Jones’s case, we have to decide which situation, given a handful of others, some in which the protagonist seems clearly guilty and some in which he/she seems clearly innocent, is most analogous to Daphne’s. The professor warned her class that analogies are “both very useful and very dangerous.” When I read this, I felt the need to both underline this phrase and dog-ear the page. I was pretty excited.

I really loved the interdisciplinary nature of this book – within a few pages, arguments were made based on St. Thomas of Aquinas’s teachings, Jeremy Bentham’s writings, and fMRI findings. As a side note, I’d advise readers to splurge on the physical copy of this book over an e-version, since the cover is a clever depiction of the original thought experiment that I wouldn’t have wanted to miss out on.

Alone Together

One of my best friends, who modestly wishes to remain anonymous, wrote this great review of one of my favorite books, Sherry Turkle’s Alone Together:

Tethered to my game of Moxie on my iPhone 4S, I find myself being bothered by the fact that I should be productive. Reluctantly, I move to another digital device, my iPad, on which I choose to draft my post. That will make it easier for me to put this together without retyping, while I spend my Friday afternoon of Labor Day weekend, wanting to sit in my yard at my pool. After I am satisfied with my draft, I can email it to the blog, not having to inconvenience myself with handwriting, rewriting, typing, printing, and mailing it. A woman of the digital age, I am.

I have wanted to write a post for this blog and my topic of choice is about a book I just finished reading – Alone Together by Sherry Turkle. There are many themes in this book, but the takeaway for me is about the use of digital devices which have such appeal to humans that we are rapidly and constantly creating significant culture changes.

We are constantly connected. Image:
We are constantly connected to others via digital devices.

The discussion is based on human behavior – how, how much, and why people are changing the ways in which we communicate, the way we play, interact with others, whom we consider to be friends, the loss of intimacy and privacy, the changes to etiquette, and basically, the enthusiastic volunteerism that is allowing the culture changes to occur. The book also covers some of the discontent that our use of our devices creates. People feel less attached, but have more attachments; people know they are less real in terms of online profiles, and they give less attention to interactions, all the while they realize that the online buddies may not be the same people offline, (how can this be satisfying?) and that they, too, are not receiving full attention in their digital interactions. And, they spend more of their precious time being with, and grooming their profiles for their online acquaintances.

There are many points to ponder, and my feel was that there is almost a mourning for “the way we were.”   I thought, sometimes, that the changes are not necessarily detrimental. In one example of this, people point out that roboticized companions for the elderly, and roboticized childcare  providers can be better than people, in some cases – people who can be hurtful and neglectful. No doubt, there are different views on the benefits and downfalls of our digital age behaviors. And there are many questions that remain to be answered.

Here, elderly patients appear to be enjoying the company of Paro, a robotic seal. Image:
Elderly patients appear to be enjoying the company of Paro, a robotic seal.

Here are two educational / clinical questions I have thought about relative to our culture shift caused by our behavior during the digital age: we are seemingly in an age of  “Attention Deficit” more and more. I say this as a parent and a teacher. I do wonder if we are preventing or even working against the development of the ability to focus. Are we untraining our attention spans, will we have less need for sustained attention, and will we evolve accordingly? In addition, we recognize far more social difficulties as disorders than ever before, under diagnoses related to the autism spectrum.  Are we damaging the natural instinct to be social creatures who intuitively learn unwritten social rules for the purpose of displaying social decorum and developing relationships? For that matter, are we helping the socially challenged child by providing him with ways to be alone, playing on tablets in the name of education, and on video game platforms for recreation? These questions are just a bit of “What’s in this Brain.”

Reflections on time

I recently finished the book Time Warped, which, according to the subtitle, “unlock[s] the mysteries of time perception.” The author, Claudia Hammond, does present a lot of intriguing studies from psychology, neuroscience, and biology to explain time, but for me, the book may actually have uncovered more mysteries than solving them.

The first intriguing point that the book brought to awareness is that time is not a thing. It’s a concept that we create in our minds, and is therefore intimately connected to our memory, concentration, emotion, and sense that it’s rooted in space. It constantly catches us off guard, for example when we’re doing something we enjoy and then realize a few hours have passed, or when we’re anticipating something and the hours seem to drag endlessly. Further, we will never get used to this phenomenon. We’ll never stop commenting on it or attempting to control and manipulate time’s passing.

Another point that really hit home for me was the possibility that our bodies likely play a part in time perception (Lately I’m wondering if any aspect of cognition is NOT linked to our bodies…). What I like about this explanation is that it leaves room for contributions by a number of brain systems and body parts to our perception of time. In short, Hammond argues that in order to perceive and measure time, we integrate information from neuronal activity in a number of areas in our brains (she makes cases for involvement of the cerebellum, basal ganglia, frontal lobe, and anterior insular cortex) and physiological symptoms of our bodies (such as physical discomfort and gut feelings- those feelings that are psychological but on the verge of physical).

Another link between our physical bodies and our perception of time was uncovered by Mark Price (paper is not yet published), who had time/space synesthetes (people who have vivid mental pictures of time- like the images below, for example) draw a diagram of how they see the months of the year. The participants then sit at a computer that randomly flashes up months on the screen, and they’re instructed to press one button for months early in the year and another for months occurring late in the year. He found that when the position of a person’s spatial representation of a month occurs in the same position as the key they need to press, they do so more quickly. For example, if March is in the left-hand corner of their mental map of the year, they’ll be quicker at hitting the key indicating that March occurs earlier in the year if that key is on the left side of the keyboard, and slower if the key is on the right side.

These are two possibilities of individuals' spatial representations of time. Image:
These are two possibilities of individuals’ spatial representations of time.

To me, this is a huge argument for embodied cognition. Time is a concept created by humans and not based in any physical thing, yet our physical body seems to have an inevitable influence over our perception of time. I wonder how much differences in our perceptiveness of bodily feelings affects our conceptualization of time…

The Time Illusion

I’ve just started the book Time Warped, which deals with our experiences of time. Time is not a thing, Claudia Hammond expresses, but instead a perception. Even though we seem to have the sense that it’s somehow rooted in space, it’s an abstract concept , and our experiences with it can be affected by so many variables.

We’re obsessed with time- the word alone is used more often than any other noun in the English language, but the word is also quite ubiquitous. The Merriam Webster entry for “time” is so long that I got bored and stopped reading around definition #10.


Chapter 1, “The Time Illusion,” is all I’ve read so far, but it’s intrigued me. Hammond first talks about how our perceptions of time are much more impressive than we tend to give them credit for. Just in holding a conversation, in order to produce and understand speech, we rely on timings that are fractions of a second (for example, we hear “pa” when the timing between the consonant and vowel is slightly longer; otherwise, we hear “ba”). Similarly, coordinating limb and muscle movements requires the estimation of milliseconds.

Empirical studies have shown that people’s sense of time is greatly affected by the situation they’re in (which is not really surprising to anyone who’s sat through a seemingly endless class, while spending hours in good company seems to fly by). When people are afraid, bored, or feeling rejected, time slows down, so these people are more likely to overestimate the amount of time that has passed. Interestingly, people with depression are also likely to give time estimations that are on average twice as long as those who aren’t depressed, giving depressed people the illusion that time is going at half its normal speed. Hammond writes, “This leads me to wonder whether in some cases depression could be considered a disorder of time perception.” An interesting take on a widely debated topic, I think.

Along these lines, she reports that children with ADHD tend to do poorly on timing tasks, again possibly because 5 minutes feels much longer to someone with ADHD. One researcher, Katya Rubia, has used time estimation tasks as a way to detect ADHD, and has correctly done so 70% of the time (Hammond also points out that there is currently no conclusive test for ADHD, so this is quite a feat). This seems to suggest to me that an abnormal sense of time may underlie many of the ailments that plague our society.

Our culture is extremely focused on time… and we also have many members who battle depression and ADHD. Is this a coincidence, or is there some connection?

I really liked Hammond’s inclusion of this quote by Saint Augustine because it reiterates the complexity of time:

“What then is time? If no one asks me, then I know. If I wish to explain it to someone who asks, I know it not.”

The Secret Life of Pronouns

I just finished The Secret Life of Pronouns: What our words say about us, as I mentioned a few days ago. I didn’t have very high expectations when I picked the book up, but this is the best depiction I have of my interest level throughout the book:

interest in pronouns

The premise of the book is very cool. It’s a true mix of computational linguistics and personality psychology, in which the focus is on function words instead of seemingly more interesting content words. The author, James Pennebaker, believes that words are “a window into the inner workings of people, a fascinating and revealing way to think about language and its links to the world around us all” (17).

Pennebaker analyzes different types of texts, and discovers trends in function word use, then applies the trends to new texts. For example, he analyzed men’s versus women’s writing and found a number of differences in the function word use by the two groups. People’s tendencies to use words like I vs. we, Pennebaker claims, can shed light not only on their gender, but also their age, mental state, and geographic location (as well as many other things).

I really liked the section where he talks about Broca’s and Wernicke’s areas. Patients with lesions on Broca’s area often have trouble stringing together words to make sentences, while those with Wernicke’s impairments often string together many words with little meaning. When Broca’s area is damaged, use of function words is impaired; when Wernicke’s area is damaged, use of content words tends to suffer. Although he admits that this is a gross oversimplification, the suggestion that the distinction between content and style words occurs at a pretty basic level in the brain is compelling.

Image: wikipedia
Image: wikipedia

The chapter on using function words to detect emotion was one of the ones that I felt like his argument was stretched a little thinly. One section, called “Arrogance, loss, and depression: The case of Mayor Giuliani and King Lear” talked about a project in which Mayor Giuliani’s speeches were analyzed. In 2000, Giuliani was diagnosed with prostate cancer, withdrew from the senate race, separated from his wife on TV before telling her, and subsequently acknowledged a “special friendship” with his future wife, Judith Nathan all within two weeks. Compared to his speeches made early in his career, after these events he had a dramatic increase in his use of I-words, a drop in big words, and an increase in his use of both positive and negative emotion words.

Pennebaker noticed that this was “eerily familiar” to Shakespeare’s King Lear, in which the king starts as an arrogant ruler, but is transformed after experiencing many traumas. Sure enough, analyzing the differences between a monologue King Lear made in Act 1, Scene 1 and one that he made in Act 5, Scene 3, Pennebaker uncovered the same function word trends that were present over the course of Giuliani’s speeches. It’s interesting, for sure, but seems to me that it could certainly be a convenient example. Plus, King Lear is a fictional character!

I think Pennebaker sums up his work pretty clearly in the last chapter:

From author identification that can help in catching criminals or in identifying historical authors, to understanding the thinking of presidents or tyrants, to predicting how people might behave in the future, function words are clues about the human psyche. Most promising, however, is that by looking at our own function words, we can begin to understand ourselves better.

I guess I would classify the book as pop linguistics- a very cool and enticing premise, even if it may be taken a little far. Regardless, it’s definitely caused me to take a second look at things I’ve said and written, wondering what aspects of myself might be revealed by words that seem, on the surface, so trivial.


As mentioned previously, I just finished Susan Cain’s Quiet: The Power of Introverts in a World that Can’t Stop Talking.


As a self-proclaimed introvert, I found it eye-opening (at times I wondered if I was reading my own biography), but I think many extroverts will find it enlightening as well. Here’s a synopsis with my personal highlights and thoughts:

In the introduction, Cain separates the concepts of “introversion” and “shyness,” a distinction that was really crucial. For sure, many introverts are shy and many shy people are introverts, but introversion at its core is different: according to Carl Jung, who coined the terms “introvert” and “extrovert,” introverts gravitate toward the inner world of thought and feeling, they focus on the meaning they make of the world around them, and they “recharge their batteries by being alone.” [10] Cain adds to Jung’s characterization by including a constellation of traits that often co-occur in introverts: they prefer less stimulation, one-on-one and in-depth conversations, and expressing themselves in writing; they enjoy solitude, listen well, take few risks, avoid conflict, work best alone, think before speaking, and have a propensity to get intensely focussed. Many are also “highly sensitive,” the psychological term for people who feel emotions especially deeply and are more sensitive than the average person to physical stimuli as well as things like music, art, and poetry.

Cain traces the history of the “extrovert ideal” in America, arguing that over time, more emphasis has been placed on charisma and vocal leadership, while the benefits of introversion have been overlooked. She also presents some evidence that collaboration may, in some cases, inhibit progress. The extrovert ideal is flawed and ignores so many contextual factors.

Another important distinction she makes is between “temperament,” our innate, biologically-based behavioral and emotional patterns, and “personality,” the “complex brew that emerges after cultural influence and personal experience are thrown into the mix” [101]. While altering our temperament is not an option, our personalities are shaped by our experiences in the world. Cain isn’t arguing that we’re born an introvert or extrovert and we’re stuck that way, but that we have the free will to affect how that temperament is manifested.

She cites examples showing that introverts and extroverts think differently. For example, it seems that extroverts’ dopamine pathways are more active than introverts’. Greater dopamine responses cause extroverts to experience greater reward buzzes and to feel more pleasure and excitement than introverts. This, in turn, is likely to encourage them to take greater risks than introverts might take in search of a reward, which has been suspected as the underlying factor for many lost fortunes when the stock market crashed- people (extroverts) were continually taking risks with hopes of obtaining a reward that never manifested. This is one of many examples of how an introvert’s way of thinking might enhance extrovert-dominated environments.

In the final section, Cain uses the differences between the two groups of people as a basis for concrete advice. First, she encourages introverts to act extroverted when it is necessary for something that’s important to them (like speaking in front of a group if it will further a career that they love). She offers suggestions to both extroverts and introverts for communicating and understanding each other, and tips for bringing out the best in introverted kids, both in the classroom and at home.

I really liked a statement she made in boiling down her argument for readers: “The secret to life is to put yourself in the right lighting. For some it’s a Broadway spotlight; for others, a lamplit desk” [264].

Guess which light I’m in right now? 🙂

The danger of group consensus

I’m almost finished reading Susan Cain’s Quiet, a guide to introversion that contradicts society’s emphasis on the extrovert ideal. Aside from the fact that I love the book (review forthcoming), one of the many studies that Cain cites sticks out in my mind. In a chapter titled “When Collaboration Kills Creativity,” she shows that the a group’s output is not always greater than the sum of each individual’s contribution; instead, it can actually be worse than one member alone might achieve.

In the study conducted by Gregory Berns*, in which 32 volunteers were shown 2 different 3D objects and asked to decide whether it would be possible to rotate the first to make it match the second. When they did this task alone, participants gave the wrong answer 13.8% of the time. When they were in a group in which members gave unanimously wrong answers, the individual gave the wrong answer 41% of the time.

This isn’t too surprising, since going against everyone else is likely to cause us to change our minds, assuming that the majority is right. The interesting part of this study comes from the fMRI data obtained while the participants made their decisions. When participants answered the question on their own, their occipital and parietal cortices, areas associated with visual and spatial perception, and the frontal cortex, and area implicated in decision-making, showed most activity. However, when they made their decision as a part of the group, the scans showed more activity in the occipital and parietal cortices and less in the frontal cortex.

The conclusion: group consensus actually changed the participants’ views of the problem. This study suggests that people don’t conform because peer pressure causes them to doubt themselves. Instead, they believe that they independently came up with the same answer put forth by the group, and therefore conform because of the power of suggestion.

This is a little frightening to me. If a group can alter our perception of a problem (and convince us to genuinely believe in an answer that’s incorrect), we should probably question the previously-unquestioned insistence that collaboration is the key to innovation and productivity. As a person who cringes every time a teacher proposes group work, I’m game.

Image from:
Image from:

*I’m repeating what Cain reports about this study because I haven’t read this book… yet.

Review of Inside Jokes

This review is thanks to my friend Dan and was originally published in volume 26 of HUMOR: The International Journal for Humor Research:

In “Inside Jokes: Using Humor to Reverse Engineer the Mind,” Daniel Dennett, along with Matthew Hurley and Reginald B. Adams Jr., attempt to build a unified theory of the development and anatomy of human humor. In this single volume, they claim to construct an overarching explanation for a wide variety of humor-related constructs, ranging from laughter to wordplay. Although Dennett is the book’s second author, “Inside Jokes” operates out of Dennett’s paradigm. His work on intentionality, memetics and evolutionary psychology serves as the philosophical backdrop to “Inside Jokes.”

The main thesis of “Inside Jokes” is that humor is an evolved adaptation used by humans to “debug” mental representations, i.e. find tacit incongruities and contradictions within representations and bring them to light. Our desire for logical consistency—formed in infancy with the development of object permanence—drives our preference for salient mental representations. For example, take this one-liner from Mitch Hedberg: “A severed foot is the ultimate stocking stuffer.” Hedberg corrects our representation of a “stocking stuffer”. One represents the “ultimate stocking stuffer” as a quality holiday gift; however, Hedberg elicits laughs by literalizing the representation based on what would best fill up some holiday hosiery? The mirth we often feel on the execution of a particularly good gag stems from the activation of a neural pleasure center, engineered over generations of selection. One’s sense of humor is a sort of cognitive sweet tooth: just as we enjoy sweets due to a Paleolithic taste for sugar, we too laugh at jokes for an innate cognitive satisfaction.

According to Hurley et al., the evolutionary origins of both humor and laughter lie in “half-serious mock-aggressive play” such as tickling or chasing. While at a glance tickling may seem to be an aggressive act, it obviously is not. In our hunter-gatherer past though, Hurley et al. speculate, violence was quick to escalate, even if based on a faulty perception. We therefore evolved laughter and smiling as a method of communicating the playfulness of the mock-aggression. They are reverse alarm-calls, common to many social primates. Humor and laughter grew concomitant through the evolution of theory of mind, the authors propose. That is, as we as a species grew more concerned with one another’s mental states, we developed methods of information transmission to infer each other’s thoughts. Laughter is one of those adaptations, allowing us to quickly delineate like-minded in-groups and different-thinking out-groups in social settings.

Following Dennett’s philosophy on memetics, the authors note that jokes are language-based cultural memes. Memetics is a subfield of evolutionary psychology, first introduced by Richard Dawkins in his 1976 book “The Selfish Gene.”  According to Dawkins and Dennett, memes are “cultural units of information” that are contained in the minds of individuals, much like genes in a genome. Memes, like genes, undergo Darwinian selection, with “fitter” memes surviving and reproducing between minds while less fit memes die off. Jokes are “self-contained mirth delivery units” that fulfill our evolved thirst for humor. Better, funnier jokes display a higher degree of evolutionary fitness Hurley et al. surmise. They are spread more rapidly between people in a manner similar to Dennett’s other “dangerous memes” such as religion and political ideology. Lame puns and childish gags face the harsh realities of selection, and are not propagated to the same extent. Because of jokes’ memetic status and humor’s deep-seated evolutionary history, Hurley et al., claim that humor is a potentially valuable tool for understanding the human mind. Because funniness comes from incongruous mental representations, the authors insist that jokes, puns, and slapstick all may afford insight into the mind, particularly the workings of the penumbra of unconscious thought. It follows from their theory that humor may allow the future researcher to “reverse engineer” our buggy mental spaces and get a glimpse into the computational maneuverings we employ to correct them.

Throughout history, theories of the brain and mind have been susceptible to becoming metaphorized to the technological innovations of the time. The fountains and pumps developed in antiquity directly influenced the Greek pneumatic picture of the soul, Enlightenment scientists identified the mind as akin to clockwork and Freud proclaimed that the unconscious held similarities to the steam-based hydraulic technology developed in the 19th century. Since World War II, the emergence of digital technology has birthed the “mind as computer” metaphor, an analogy championed by Hurley, Dennett et al. The authors’ conception of humor as a cognitive “debugging” aligns well with contemporary computational accounts of the mind. Thus, digital-age readers may be inclined to find credence in Hurley et al.’s work as it overlays nicely with today’s popular psychological metaphors. “Inside Jokes” though does not go beyond these metaphors and will disappoint old-fashioned readers, since it offers little beyond an update in underlying metaphors.