This week we write about intelligence, and how it can be affected by environmental factors. We focus on working memory, which when exercised can improve fluid, problem-solving intelligence. Practice on such a task can raise your IQ by at least four points, on average. Check it out…

Air time is the same everywhere because of rebroadcast. You can also go to the Today website to read an excerpt and take the quiz.

…actually, our book will be on, but we won’t. Dr. Nancy’s doing a segment called “Welcome To Your Brain.” Tune in at 8:09am (the same in all time zones because of rebroadcast). You can also go to their website to read an excerpt and take our quiz.

Update: what a nice piece. Nancy Snyderman covered many topics from the book, and she clearly enjoyed it. To see the segment, go to one of these sites: [MSNBC] [Hulu] [synapse.princeton.edu]

This is the measure of where things really stand – not the top-line estimate above, which still includes many pre-convention state polls.

The polls (Pollster, RCP) come from

• Gallup Daily Tracker (McCain +4%)
• Fox/Opinion Dynamics (R) (McCain +3%)
• Democracy Corps (D) (McCain +2%)
• Diageo/Hotline Tracking (McCain +2%)
• Rasmussen Tracking (tie)
• InsiderAdvantage (tie)
• DailyKos/Research 2000 (D) (Obama +2%)

Update: adding DailyKos/R2000 increased the error bar without changing the median.

As state polls pour in, the unadjusted, state-polls-only estimator is catching up with the adjustment. This is important because we do not know where the shift occurred. For example, if the change was in strongly Obama or McCain-leaning states, the true estimate will be closer. The converse is true as well.

By the end of the weekend we will have a precise state-level view of where the candidates stand in the Electoral College.

Also, we are still learning new information about Sarah Palin. For instance, while mayor of Wasilla she made rape victims pay for their own forensic tests. This was reported in 2000 by the local newspaper there, the Frontiersman. This is a particularly interesting story because she also drove the town $22 million into debt to buy things like a sports complex. This could affect opinion.

The eight weekend polls span September 5-7 and are the most recent available from Gallup Tracking, Rasmussen Tracking, Diageo/Hotline, USA Today/Gallup, CNN, Zogby Interactive, ABC/Washington Post, and CBS. They draw upon over 11,000 respondents. Two polls have been added, added in italics.

Based on the correction to pre-convention state polls I provided last week, applying the national margin as a correction to the Meta-Analysis gives a median EV estimate of McCain 300 EV, Obama 238 EV. The 95% confidence interval is McCain [268-338] EV, Obama [200-270] EV.

Omitting data from Zogby Interactive, a poll that is known to be of low data quality, makes no difference in the margin and therefore no difference in the EV estimate or 95% confidence interval.

Matched comparisons with the six polls previously reported gives a bounce for McCain of 9.5 +/- 2.2%.

Sources: Pollster.com, RealClearPolitics.

A prime example of a realignment is the dominance of the Democratic Party in the South, which was more or less unbroken from 1840 to 1960. A shift occurred during Lyndon Johnson’s presidency, when he pushed the Civil Rights Act through Congress as part of Kennedy’s legacy. At the time he told an aide “we have lost the South for a generation.” This was an underestimate.

It will be at least a week before state polls will show us where the post-convention race stands. In fact, it’s been a polling desert for at least a week, as you can see from the flat part of the history graph. Until then, the best indicator will be national polls. How to convert them to an EV estimate? The answer is in the following graph.

EV adjustment curve with pre-convention polls except AK

(Click the figure to get a higher-resolution version for reading off values)

The graph was generated starting from the most recent pre-convention state polls, which are basically a pre-Democratic convention snapshot. Because some of them are pre-8/21, they do not even fully reflect the post-”Seven” bounce. The exception is Alaska, which is now assumed to be McCain +20. At that time, in national polls Obama led McCain by 3%. Then a range of offsets was added, and the Meta-Analysis was redone. Use the current national polling margin, which you can get from Pollster.com or RealClearPolitics, to get a corrected median EV estimator. As of the evening of 9/4, national polls taken immediately before the Palin speech give a median of Obama +5%, corresponding to Obama 324 EV, McCain 214 EV.

The gray band indicates the 95% confidence band, assuming an uncertainty of +/-1% in national margins, close to what I calculated before.

This graph can also be used to calculate the effect of systematic polling error. An example of systematic error that favors McCain is the possibility that polling margins overstate the relative support for Obama because of racial bias (the Bradley/Wilder effect). An example that favors Obama is the fact that people who have a cell phone but no landline, and are therefore missed in conventional surveys, skew strongly toward Obama. You can add in your own assumptions and read the result. I’ll provide an updated version of this graph as the election approaches.