So some of the smallest most insignificant work
is everyday, cos reflect a lot about who we are.
And I say this not as a linguist,
or a computer scientist but as a social psychologist.
And today I'd like to tell you a story
that summarizes a lot of the research
that my colleagues, my students and I have done,
that have helped me to come to this realization.
Now several years ago I was studying the nature of traumatic experience
and how it is related to physical health
and kept finding that just completely perplexed me.
Basically when people have a major traumatic experience in their life,
they are much more likely to get sick after that event,
if they keep the events secret,
than if they actually talk to other people.
So, this really bugged me. So keeping a secret it seems
is somehow toxic.
So this led me to run some experiments
where we brought people in the laboratory
and we asked them to write about
the most traumatic experiences they've had, especially if they'd kept them secret.
And these were big traumas, these were things like rape.
They were like major public humiliations or failure.
And the results that we got from this this study were stunning.
We discovered that having people write as little as fifteen minutes a day,
for 3 or 4 consecutive days,
brought about meaningful changes in people's physical health
and even their immune function.
Translating up, saying experiences into words makes a difference, but why?
Since then there have been hundreds of studies done by labs all over the world
trying to answer this and they haven't come up with a single explanation.
My own approach was to actually look at the essays that these people wrote,
and try to figure out,
was there something about the essays that could predict
who would benefit from writing versus who wouldn't?
I tried and I couldn't figure it out.
So I got a number of psychologists and other experts
to read and write hundreds of these essays,
and they couldn't see a pattern either;
I needed to try some other strategies.
So, with the help of one of my graduate students,
Martha Francis, we wrote a computer program.
And the idea of this computer program was to go into any given text
and calculate the percentage of words in their texts
that were positive emotion words, negative emotion words
or words related to topics such as death or sex or violence or religion or family.
And as long as we were writing the computer program,
I thought well let's go ahead and throw in some parts of speech,
pronouns, prepositions. Why? Because it was easy, who cares?
So, I go back, start to analyze these traumatic essays,
and quickly discover that the content of what people were writing about
didn't matter in terms of if they improved in their health or not,
instead, it was these junk words, pronouns, articles, prepositions and so forth
that did matter. Now think about this.
Here people are writing about deeply disturbing issues
and the actual topics that dealt with tragedies, devastation, horrible things,
the topics themselves and the words associated
with those topics made no difference.
Instead these little words like "I" and "the" and "and" did matter.
I'd been looking for the obvious, but in fact
I'd been paying attention to what people were saying,
but not how they were saying it.
So how do I go about analyzing what verus how?
Well, it turns out that they're different kinds of classes of words
that look at this distinction, and one of them is
if you're looking at what people are writing about,
you look at what are called content words. These are nouns and regular verbs
and adjectives and some adverbs. These are the stuff of thought,
these were the stuff of communication. We were trying to talk to somebody.
Google and search terms are all based on these content words.
The other group of words are a class of words
that are generally called function words.
And function words are made up of the most boring words you can imagine.
They're made up of pronouns: "I", "me", "he", "she";
prepositions: "to", "of", "for"; auxillary verbs: "am", "is", "have" â
I'll have to wake you up if I keep talking about these function words.
But it turns out these function words are really interesting,
because, first of all, there's only about five hundred function words in English,
so they account for far less than 1% of all the words we know, we hear, we read.
Nevertheless, they reflect 55% to 60% of all the words that we are surrounded with,
they're everywhere, but we don't pay attention to them.
In English and in other languages, they're the shortest words there are,
and when they're spoken or when you're reading,
they zip into your brain at the speed of less than 0.2 seconds,
meaning that they're processed essentially non-consciously.
But there's something even more interesting about them,
they are social, they are profoundly social.
Let me give me an example, let's say you're walking along,
you see a note on the ground, you pick it up and it says,
"I am placing it on the table."
Well, that kinda makes sense, kinda doesn't.
"I'm placing it on the table" â there's 2 content words, "placing" and "table";
all the rest are function words:
"I", "am", "it", "on", "the".
Now the reason this doesn't make sense to most of us is
who was "I"? No idea.
"Am" implies present tense. When was it written?
"It"? Pfft, no idea what "it" is.
"On the table", "the table" means it's a table
that the author knew about
and the intended recipient of this note knew about,
but nobody else did. And, in fact, this note only has meaning to the author
and the recipient of the note
at a particular time, in a particular location.
And, in fact, if I took that note to this author 6 months later and say,
"What's this all about?" there's a good chance that the author will say,
"No idea."
Function words are social,
they tell us about the author, they tell us about the relationship
between the author and the recipient
and the relationship between the author and the topic itself.
And this is the heart of what I want to talk to you about today.
By analyzing function words we start to get a sense
of who people are, what their relationships are,
how they think about theirselves and how they connect with others.
Yeah, there're a lot of function words,
and honestly I could talk for several hours about function words,
but I'm going to spare you that and just focus on a couple today
to just give you a flavor of why they're so interesting.
Let's start off with pronouns, and let's start off with third-person pronouns
like "he", "she", "they".
Now it turns out some people out there in the world
use these third-person pronouns at high rates
and other people at low rates.
What kind of person would use them?
Well, you have to think about pronouns and all function words
in terms of where are people paying attention.
If you are using these third-person pronouns,
by definition you're paying attention to other people.
You care about other people, you're thinking about other people,
and people who use these at high rates
are much more socially engaged.
We can analyze emails, tweets and so forth
and get a sense of someone's social engagement just by looking at this.
How about first-person singular pronouns, "I", "me" and "my"?
OK, using the attentional arguments
someone who's attending to their thoughts, feelings,
behaviors, to themselves in some way would use these words more.
What kind of person do you think uses "I" words the most?
I hope, you're sitting there, you're thinking, "Well, somebody who's
self-centered, self-important, narcissistic,
hungry for power and high in status."
You would be completely wrong.
In fact the person who is highest in status uses "I" words the least.
Let me rephrase that,
the higher anybody is in status, the less they use "I" words;
the lower someone is in status, the higher they use a "I" words.
Now, I discovered this by analyzing emails,
instant messages, natural conversations, business groups and so forth.
And the affects were huge. I looked at these results and I thought,
"Wow, this must be true for other people but it can't possibly be true for me."
You know I love everybody equally. So I go in and analyze my own emails.
I'm the same as everybody else,
I look at the email that I get from an undergraduate student,
"Dear Dr Pennebaker, I would like to know if I could possibly meet with you
because I think I need to change my grade."
And I write back, "Dear Student, Thank you so much for your email.
Unfortunately, the way the grade systems work, blah, blah, blah."
I look at my email to the dean.
"Dear Dean, I'm Jamie Pennebaker and I would like to ask you
if I could do this and if I could do that and I could do this."
And the dean writes back, "Dear Jamie,
Thank you so much for your email..." and so forth.
Now everybody is being completely polite, nobody's putting anybody down.
This is the language of power in status;
it tells us where people are paying attention.
A high status person is looking out at the world,
the low status person tends to be looking more inwardly.
What about others states?
Let's move beyond status, let's look at emotional states.
You would think that someone would be paying more attention to themselves
if they're in pain. It could be physical pain or emotional pain.
In fact, if we look at people who are depressed,
we've done many studies on this, we know that people who are depressed
pay attention to themselves more and they used the word "I" more.
In fact one of our very first studies looked at the poetry
of suicidal and non-suicidal poets.
Now we did this research where we went through, analyzed their poetry,
and initially I thought, where the big difference
in the degree to which they use negative and emotional words.
Not true.
Suicidal and non-suicidal poets all use negative emotion words at high rate.
I think it's part of the job description.
The big difference was their use of the word "I",
suicidal poets use the word "I" more.
Consider this poem, this is by Sylvia Plath who later committed suicide.
Listen to the way that she uses the word "I" and first-person singular.
I'm taking some lines from her poem "Mad Girl's Love Song".
I shut my eyes and all the world drops dead;
I lift my lid[s] and all is born again.
(I think I made you up inside my head.)
I fancied you'd return the way you said, But I grow old and I forget your name.
(I think I made you up inside my head.)
You can almost see Plath
embracing her sorrow, her misery and so forth
and you can compare her writing with other poets, non-suicidal poets
who write about lost love.
When they do, you can almost see them holding it off from a distance,
so they're looking at it from a more distance, third-person perspective.
Now there's a really interesting, important theory within psychology
about depression. And people who are depressed
are thought to be people who are very high in self-awareness or self-focus.
And part of this is they also tend to be extremely honest.
In fact there are many studies showing that they have this deficit
and they're not able to have positive illusions about ourselves.
Those of us who aren't depressed get by every day
by holding these insane illusions about the life.
But these people are brutally honest.
Now this made me wonder, throw away depression for just a second.
Could we turn this entire thing upside down and find out if depressed people
or if we could use a computer program as a linguistic lie-detector.
I mean for anybody. So in fact we did some studies,
where we brought people in the lab, we induced them to lie or tell the truth,
we analyze court transcripts of people who were all found guilty,
the half of whom were later exonerated,
and the affects were really quite impressive.
We did a pretty good job at telling
if someone who was telling the truth versus lying,
and one of the best words was the use of the word "I".
People who tell the truth use the word "I" more, owning what they're saying.
Liars are tending to hold off, distancing themselves.
Now, lie-detection and depression, status are all some things that we can look at,
But one of the things that I'm most interested in now is looking at groups,
looking at the relationship between two people.
Can you tell how two people are getting along
by analyzing the way that they're using function words with each other?
And the answer is yes. We look at the percentage of each class of words
and we come up with the metric that we call language style matching.
And the more that two people are matching in their function word use,
the more they're on the same page,
the more they're talking about something in the same way.
Now one place we started to look at this was with speed dating.
Now, I should tell you I love speed dating, I would never do it in a million years,
but I encourage all of you to go do speed dating and when you do,
invite a researcher along because there is no paradigm that is better.
We've been involved in speed-dating projects
where people come in and in their four minute date, we tape-record it,
they know we are, and then we transcribe the way they talk.
The more they match in their language,
the more likely they are to go out on a date.
We can predict who will go on a date
at rates slightly better than the people themselves can.
We've done studies with young dating couples.
To be in our study they had to give us 10 days of their instant messages or IM's.
And then what we do is we analyze their IM's with this style matching
and we do much, much better than they do
at predicting if they'll be together 3 months later.
The fact is, is these words are telling us how individuals
and pairs of people are connecting.
What about groups. Now this is an area that we're now working at.
We're looking at working groups, some are groups that we've worked with,
people from the business school, we look at people in the get-to-know-you groups,
we do educational groups. And what we're finding is
by looking at a group of say 5 or 6 people, we can now get a sense
of how productive the group will be, and also how cohesive the group wil be,
simply by looking at the style matching.
Now here's where things are beginning to get interesting:
by tracking a group that's interacting and say they're all interacting online,
we can have a computer monitoring how the group is behaving.
Imagine for example you are in this group and a computer coach comes to your group
every now and then, and a message comes and says,
"You guys are not paying attention to one another,
you need to be more attentive to what the other people are saying," or
"You guys for the last few minutes have strayed off topic,
try to get back on topic," or that loud mouth in the group,
the computer comes in and says, "John, for the last 5 minutes
you said 50% of the words, why don't you stand back
and courage others to talk?"
Well, we have now created a program that does this,
and we've now tested it out with hundreds of groups
and we are getting very promising results.
Now you can start to see why I'm so excited about this world of function words,
that we're now taking this in all these directions,
that I never would've thought about.
We've been looking at it in terms of looking at historical records.
Can you tell if a particular explorer committed suicide or was murdered?
We've done a project on that.
Can you look at a company and get a sense
of how their internal communications are working?
How well they are connecting with the people in their company or with their clients?
We look at corporate earnings reports or the quarterly phone calls
to get a sense of the internal group dynamics of the company.
We've worked with the government to try to get a sense of terroist groups
and if they are likely to behave badly.
We've helped people sort out their love lives.
You can start to see that by harnessing the power of these function words
We can get a sense of individuals and groups and how people are connecting.
Now what I would urge you to do, I'd like you to go home tonight
and I want you to start looking at your emails,
your tweets, your IM's or whatever,
and in doing that what I hope you start to see,
first of all you learn a little bit more about your relationships with others,
but more than anything I hope you learned a little bit about yourself.
Thank you very much.
(Applause)