The purpose of this post is to provide basic information about the LSAT including the format of the test and a few sample questions. I also wanted to bring light to some research that has found LSAT preparation to alter brain structure in ways that strengthen hypothesized "reasoning pathways". These studies have not been discussed here before; I thought they were interesting and really just wanted to call your collective attention to them.

I really like taking tests; I get energized by intense race-against-the-clock problem solving and, for better or worse, I relish getting to see my standing relative to others when the dust settles. I like the the purity of the testing situation --how conditions are standardized in theory and more or less the same for all comers. This guilty pleasure has played no small part in the course my life has taken: I worked as a test prep tutor for 3 years and loved every minute of it, I met my wife through academic competitions in high school, and I am a currently a graduate student doing lots of coursework in psychometrics.

Well, my brother-in-law is a lawyer, and when we chat the topic of the LSAT has served as some conversational common ground. Since I like taking tests for fun, he suggested I give it a whirl because he thought it was interesting and felt like it was a fair assessment of one's logical reasoning ability. So I did, I took a practice test cold a couple Saturdays ago and I was very impressed. Here the one I took. (This is a full practice exam provided by the test-makers; it's also like the top google result for "LSAT practice test".) I wanted to post here about it because the LSAT hasn't been discussed very much on this site and I thought that some of you might find it useful to know about.

A brief run-down of the LSAT:

The test has four parts: two Logical Reasoning sections, a Critical Reading section (akin to SAT et al.), and an Analytical Reasoning, or "logic games", section. Usually when people talk about the LSAT, the logic games get emphasized because they are unusual and can be pretty challenging (the only questions I missed were of this type; I missed a few and I ran out of time). Essentially, you get a premise and a bunch of conditions from which you are required to draw conclusions. Here's an example:

A cruise line is scheduling seven week-long voyages for the ship Freedom. 
Each voyage will occur in exactly one of the first seven weeks of the season: weeks 1 through 7. 
Each voyage will be to exactly one of four destinations:Guadeloupe, Jamaica, Martinique, or Trinidad. 
Each destination will be scheduled for at least one of the weeks. 
The following conditions apply: Jamaica will not be its destination in week 4. 
Trinidad will be its destination in week 7. Freedom will make exactly two voyages to Martinique, 
and at least one voyage to Guadeloupe will occur in some week between those two voyages. 
Guadeloupe will be its destination in the week preceding any voyage it makes to Jamaica. 
No destination will be scheduled for consecutive weeks.

11. Which of the following is an acceptable schedule of destinations in order from week 1 through week 7?

(A) Guadeloupe, Jamaica, Martinique, Trinidad,Guadeloupe, Martinique, Trinidad
(B) Guadeloupe, Martinique, Trinidad, Martinique, Guadeloupe, Jamaica, Trinidad
(C) Jamaica, Martinique, Guadeloupe, Martinique, Guadeloupe, Jamaica, Trinidad
(D) Martinique, Trinidad, Guadeloupe, Jamaica, Martinique, Guadeloupe, Trinidad
(E) Martinique, Trinidad, Guadeloupe, Trinidad, Guadeloupe, Jamaica, Martinique

Clearly, this section places a huge burden on working memory and is probably the most g-loaded of the four. I'd guess that most LSAT test prep is about strategies for dumping this burden into some kind of written scheme that makes it all more manageable. But I just wanted to show you the logic games for completeness; what I was really excited by were the Logical Reasoning questions (sections II and III). You are presented with some scenario containing a claim, an argument, or a set of facts, and then asked to analyze, critique, or to draw correct conclusions. Here are most of the question stems used in these sections:

Which one of the following most accurately expresses the main conclusion of the economist’s argument?
Which one of the following uses flawed reasoning that most closely resembles the flawed reasoning in the argument?
Which one of the following most logically completes the argument?
The reasoning in the consumer’s argument is most vulnerable to criticism on the grounds that the argument...
The argument’s conclusion follows logically if which one of the following is assumed?
Which one of the following is an assumption required by the argument?

Heyo! This is exactly the kind of stuff I would like to become better at! Most of the questions were pretty straightforward, but the LSAT is known to be a tough test (score range: 120-180, 95th %ile: ~167, 99th %ile: ~172) and these practice questions probably aren't representative. What a cool test though! Here's a whole question from this section, superficially about utilitarianism:

3. Philosopher: An action is morally right if it would be reasonably expected
to increase the aggregate well-being of the people affected by it. An action
is morally wrong if and only if it would be reasonably expected to reduce the 
aggregate well-being of the people affected by it. Thus, actions that would 
be reasonably expected to leave unchanged the aggregate well-being of the
people affected by them are also right.

The philosopher’s conclusion follows logically if which one of the following is assumed?

(A) Only wrong actions would be reasonably expected to reduce the aggregate 
 well-being of the people affected by them.
(B) No action is both right and wrong.
(C) Any action that is not morally wrong is morally right.
(D) There are actions that would be reasonably expected to leave unchanged the
  aggregate well-being of the people affected by them.
(E) Only right actions have good consequences.

Also, the LSAT is a good test, in that it measures well one's ability to succeed in law school. Validity studies boast that “LSAT score alone continues to be a better predictor of law school performance than UGPA [undergraduate GPA] alone.” Of course, the outcome variable can be regressed on both predictors and account for more of the variance than either one taken singly, but it is uncommon for a standardized test to beat prior GPA in predicting a students future GPA.

Intensive LSAT preparation and neuroplasticity:

In two recent studies (same research team), learning to reason in the logically formal way required by the LSAT was found to alter brain structure in ways consistent with literature reviews of the neural correlates of logical reasoning. Note: my reading of these articles was pretty surface-level; I do not intend to provide a thorough review, only to bring them to your attention.

These researchers recruited pre-law students enrolling in an LSAT course and imaged their brains at rest using fMRI both before and after 3 months of this "reasoning training". As controls, they included age- and IQ-matched pre-law students intending to take LSAT in the future but not actively preparing for it.

The LSAT-prep group was found to have significantly increased connectivity between parietal and prefrontal cortices and the striatum, both within the left hemisphere and across hemispheres. In the first study, the authors note that

These experience-dependent changes fall into tracts that would be predicted by prior work showing that reasoning relies on an interhemispheric frontoparietal network (for review, see Prado et al., 2011). Our findings are also consistent with the view that reasoning is largely left-hemisphere dominent (e.g., Krawczyk, 2012), but that homologous cortex in the right hemisphere can be recruited as needed to support complex reasoning. Perhaps learning to reason more efficiently involves recruiting compensatory neural circuitry more consistently.

And in the second study, they conclude

An analysis of pairwise correlations between brain regions implicated in reasoning showed that fronto-parietal connections were strengthened, along with parietal-striatal connections. These findings provide strong evidence for neural plasticity at the level of large-scale networks supporting high-level cognition.

I think this hypothesized fronto-parietal reasoning network is supposed to go something like this:

The LSAT requires a lot of relational reasoning, the ability to compare and combine mental representations. The parietal cortex holds individual relationships between these mental representations (A->B, B->C), and the prefrontal cortex integrates this information to draw conclusions (A->B->C, therefore A->C). The striatum's role in this network would be to monitor the success/failure of reward predictions and encourage flexible problem solving. Unfortunately, my understanding here is very limited. Here are several reviews of this reasoning network stuff (I have not read any; just wanted to share them): Hampshire et al. (2011), Prado et al. (2011), Krawczyk (2012).

I hope this was useful information! According to the 2013 survey, only 2.2% of you are in law-related professions, but I was wondering (1) if anyone has personal experience studying for this exam, (2) if they felt like it improved their logical reasoning skills, and (3) if they felt that these effects were long-lasting. Studying for this test seems to have the potential to inculcate rationalist habits-of-mind; I know it's just self-report, but for those who went on to law school, did you feel like you benefited from the experience studying for the LSAT? I only ask because the Law School Admission Council, a non-profit organization made up of 200+ law schools, seems to actively encourage preparation for the exam, member schools say it is a major factor in admissions, preparation tends to increase performance, and LSAT performance is correlated moderately-to-strongly with first year law school GPA (r= ~0.4).