Field of Science

Findings: What do verbs have to do with pronouns?

A new paper, based on data collected through, is now in press (click here for a pre-print). Below is an overview of this paper.

Unlike a proper name (Jane Austen), a pronoun (she) can refer to a different person just about every time it is uttered. While we occasionally get bogged down in conversation trying to interpret a pronoun (Wait! Who are you talking about?), for the most part we sail through sentences with pronouns, not even noticing the ambiguity.

We have been running a number of studies on pronoun understanding (for some previous posts, see here and here). One line of work looks at a peculiar contextual effect, originally discovered by Garvey and Caramazza in the mid-70s:
(1) Sally frightens Mary because she...
(2) Sally loves Mary because she... 
Although the pronoun is ambiguous, most people guess that she refers to Sally in (1) but Mary in (2). That is, the verb used (frightens, loves) seems to affect pronoun resolution.

Causal Verbs

From the beginning, most if not all researchers agreed that this must have something to do with how verbs encode causality: "Sally frightens Mary" suggests that Sally is the cause, which is why you then think that "because she…" refers to Sally, and vice versa for "Sally loves Mary".

The problem was finding a predictive theory: which verbs encode causality which way? A number of theories have been proposed. The first, from Harvard psychologists Roger Brown and Deborah Fish (1983) was that for emotion verbs (frightens, loves), the cause is the person who *isn't* experiencing the emotion -- Sally in (1) and Mary in (2) -- and the subject for all other verbs. This turned out not to be correct. For instance:
(3) Sally blames Mary because she...
Here, most people think "she" is Mary, even though this is not an emotion verb and so the "cause" was supposed to be -- on Brown and Fish's theory -- the subject (Sally).

A number of other proposals have been made, but the data in the literature doesn't clearly support any one (though Rudolph and Forsterling's 1997 theory has been the most popular). In part, the problem was that we had data on a small number of verbs, and as mathematicians like to tell us, you can draw an infinite number of lines a single point (and create many different theories to describe a small amount of data).

Most previous studies had looked at only a few dozen. With the help of visitors to, we collected data on over 1000 verbs. (We weren't the only ones to notice the problem -- after we began our study, Goikoetxea and colleagues published data from 100 verbs in Spanish and Ferstl and colleagues published data from 305 in English). We found that in fact none of the existing theories worked very well.

However, when we took in independently developed theory of verb meaning from linguistics, that actually predicted the results very well. All of the theories tried to divide up verbs into a few classes. Within each class, it was supposed to be all the verbs with either have causes as their subjects (causing people to interpret the pronoun is referring to the subject in sentences like 1-3). Unfortunately, this was rarely the case, as shown in Table 2 of the paper:

A new theory

This was, of course, disappointing. We wanted to understand pronoun interpretation better, but now we understood worse! Luckily, the work did not end there. We turned to a well-developed theory from linguistics about what verbs mean (the work I have described above was developed by psychologists largely independently from linguistics).

The basic idea behind this theory is that the core meaning of verbs is built out of a few basic parts, such as movement, possession, the application of force, and – importantly for us – causality. In practice, nobody goes through the dictionary and determines for every verb, which of these core components it has. This turns out to be prohibitively difficult to do (but stay tuned; a major new project will be focused on just this). But it turns out that when you classify verbs according to the kinds of sentences they can appear in, this seems to give you the same thing: groups of verbs that share these core components meaning (such as causality).

The prediction, then, is that if we look at verbs in the same class according to this theory, all the verbs in that class should encode causality in the same way and thus should affect pronouns in the same way. And that is exactly what we found. This not only furthers our understanding of the phenomenon we were studying, but it is also confirmation of both the idea that verb meaning plays a central role in the phenomenon and is confirmation of the theory from linguistics.

Why so much work on pronouns?

Pronouns are interesting in their own right, but I am primarily interested in them as a case study in ambiguity. Language is incredibly ambiguous, and most of the time we don't even notice it; For instance, it could be that the "she" in (1) refers to Jennifer -- someone not even mentioned in the sentence! -- but you probably did not even consider that possibility. Because we as humans find the problem so easy, it is very hard for us as scientists to have good intuitions about what is going on. This has become particularly salient as we try to explain to computers what language means (that is, program them to process language).

The nice thing about pronouns is that they are a kind of ambiguity is very easy to study, and many good methods have been worked out for assessing their processing. More than many areas of research on ambiguity -- and, I think, more than many areas of psychology that don't involve vision -- I feel that a well worked-out theory of pronoun processing is increasingly within our reach. And that is very exciting.


Hartshorne, J., and Snedeker, J. (2012). Verb argument structure predicts implicit causality: The advantages of finer-grained semantics Language and Cognitive Processes, 1-35 DOI: 10.1080/01690965.2012.689305

Brown, R., and Fish, D. (1983). The psychological causality implicit in language Cognition, 14 (3), 237-273 DOI: 10.1016/0010-0277(83)90006-9

Goikoetxea, E., Pascual, G., and Acha, J. (2008). Normative study of the implicit causality of 100 interpersonal verbs in Spanish Behavior Research Methods, 40 (3), 760-772 DOI: 10.3758/BRM.40.3.760

Ferstl, E., Garnham, A., and Manouilidou, C. (2010). Implicit causality bias in English: a corpus of 300 verbs Behavior Research Methods, 43 (1), 124-135 DOI: 10.3758/s13428-010-0023-2

Rudolph, U., and Forsterling, F. (1997). The psychological causality implicit in verbs: A review. Psychological Bulletin, 121 (2), 192-218 DOI: 10.1037//0033-2909.121.2.192

1 comment:

Anonymous said...

I think you should replace your "daxes" with real words, it may be difficult to imagine the situation (at least, for a non-native speaker) when the whole sentence revolves around some obscure "dax", I even had to abandon the test because I couldn't choose one option.