Drew Westen’s The Political Brain: The Role of Emotion in Deciding the Fate of the Nation came out about a month after my Myth of the Rational Voter. Our sales have been neck-and-neck on Amazon for a long time. But it’s only now that I’ve gotten around to reading the competition.

There’s definitely some good material in Westen’s book. He does a great job of distancing himself from narrow “bounded rationality” models of political behavior. The main problem with rational voter models, he and I agree, isn’t that voters lack the computing power to formally derive optimal solutions; the problem is that most voters just don’t use their heads. Instead, they approach politics emotionally: What do I feel is true? Who do I like? Does this leader make me feel proud? Etc.

So far, so good. But once you move beyond this basic message, The Political Brain repeatedly misses the mark.

1. Despite the title and passing references, this book has virtually nothing to do with brain science. It’s a work of political psychology, not political neurology. There isn’t an argument in this book that Shakespeare couldn’t have understood. To say, “Bush’s words activated the X region of people’s brains, making them angry with Democrats, so they voted against Kerry” adds nothing to “Bush’s words made people angry with Democrats, so they voted against Kerry.” Admittedly, this is not a unique flaw with Westen’s book; it applies to virtually all attempts to make neuro-science “relevant” to social science.

2. You’d think that Westen’s analysis would make him slightly self-critical. If emotions have a big influence on our political views, Westen should at least occasionally wonder, “Are my emotions biasing my analysis?” But he never does – and it shows.

Here’s just one example: His claim that Republicans are vastly better at manipulating political emotions than Democrats:

Republicans have a keen eye for markets, and they have a near-monopoly in the marketplace of emotions. They have kept government off our backs, torn down the wall, saved the flag, left no child behind, protected life, kept our marriages sacred, restored integrity to the Oval Office, spread democracy in the Middle East, and fought an unrelenting war on terror. The Democrats, in contrast, have continued to place their stock in the marketplace of ideas.

This may feel true to Westen. But what’s his evidence? All he really shows is that Gore and Kerry ran emotionally inept campaigns. But two lame Democratic candidates are hardly strong evidence for a massive partisan gap in emotional intelligence. And if Westen tried to come up with equally awkward Republican presidential contenders, it would have been easy. Ford? Bush I? Bob Dole?!

Similarly, for Westen to rattle off emotion-laden Republican slogans is underwhelming. Democrats have an equally massive collection: Protecting regular Americans from greedy corporations, saving the planet, declaring war on poverty, making sure that every American has X, “hate is not a family value,” etc. And while it’s true that Democrats have a lot more Ph.D.s on their side in the “marketplace of ideas,” virtually all Democratic politicians know better than to publicly campaign on a platform written by social scientists.

Finally, if emotions are what really matters in politics, and Republicans are vastly better at playing the emotional game than Democrats, why are so many Democrats in office? Westen repeatedly cites Republican control over the presidency in the post WWII era, but if you broaden your sample to include Congress, state governments, and the judiciary, it’s pretty clear that the two parties have had roughly equal power since 1945. The obvious explanation is that Democratic politicians are, on average, about as good at manipulating emotions as Republican politicians. The perception of a wide difference is just availability bias: For Westen, the presidential losses of 2000 and 2004 are so vivid that they drown out thousands of other data points.

3. Westen spends a lot of time telling Democrats what they should have said, and need to start saying. And he’s quick to dismiss mainstream Democratic political strategists as fools. But he never wonders whether emotion is clouding his judgment: If Westen’s speeches inspire Westen himself, they must be electoral gold! But I suspect that mainstream Democratic strategists would correctly respond that Westen’s speeches are great for Democratic primaries, but too extreme and polarizing to win in a general election.

4. The most amazing thing about Westen’s book, to me, is his emotional reaction to his main results. He’s strangely indifferent to the fact that liberals, conservatives, and moderates lack the intellectual integrity to calm down and carefully weigh the facts before endorsing policies. After documenting the overwhelming power of emotion in politics, his only concern is to help his side build a better demagogue.

Here’s my closing question for Westen: Given your findings, isn’t it premature to try to figure out a way to get the Democrats back in power? Shouldn’t your main concern be to put aside your own emotional biases and figure out who’s got truth on their side, issue-by-issue?

Westen might want to object to the whole idea of “truth” in this context. But come on! Even if your fundamental values are not open to rational criticism, the best means of pursuing them surely are.