This is a deeply flawed book. It purports to be a description of the characteristics and attitudes that make wealthy people wealthy, but it is based mostly on their self-assessments without comparison to a control group. I suspect that this heavily underplays the role of random chance in success, and attributes causation where there is only correlation. Further, the author display clear biases on a number of topics, which leads him to engage in ad hoc interpretation of his data, sometimes to argue for conclusions that are contrary to the clear implications of the data--such as his arguments for the importance of religion in the lives of millionaires.
On pp. 33-35, the author looks at success factors, and compares to the role of luck on pp. 82-85, which he downplays in favor of discipline. While he touches on the importance of having the right connections (and the genetic contributions to intelligence), on p. 85 he asks "what does luck have to do with graduating from medical school? What does luck have to do with successfully running a medical practice? Very little, according to these physicians." But what does luck have to do with being born into a family and in a country where one has a chance to reach adulthood, let alone be able to attend a medical school? Quite a bit.
Unlike its predecessor, which looked at prodigious accumulators of wealth (PAWs) vs. under-accumulators of wealth (UAWs), this book focuses on millionaires (PAWs) and decamillionaires (a tiny subset of PAWs, those with net worth $10M or greater). The lack of comparison to the general public serves to limit the book's value.
A misleading comparison between businessmen and stockbrokers on pp. 76ff makes the point. Stanley states that the former is an occupation more likely to have higher net worth. But this comparison is misleading because he's only looking at the millionaire-plus sample; he is excluding more of the total business owner population from his sample than stockbrokers. The average and median income and net worth for business owners are likely lower than for stockbrokers. If he made the same comparison with actors or musicians to stockbrokers, for example, the problem is more obvious--by excluding all those who aren't worth $1M or more up front, you exclude the vast majority, and pull up the average. With stockbrokers, on the other hand, a higher percentage of them are in the top income earners and wealthy.
On p. 110, after having pages about the importance of ethics and advising "Never lie. Never tell one lie." (p. 55), he passes right over his example, Mr. Warren, lying about being a college graduate in order to get a job, without comment, and without noticing the hypocrisy.
On pp. 173-174, the author wants to make the point that prayer is important for millionaires dealing with stress, despite the fact that the majority of his surveyed population do not regularly pray. (He repeats this again on p. 370, saying "nearly one-half of the millionaires (47 percent) engaged in prayer. ... for a significant percentage of millionaires, their religious faith is a major force in their lives.")
In trying to emphasize the point (p. 174), he splits his sample into "religious millionaires" (RM) and "other millionaires" (OM), observes that 75% of RM engage in prayer while only 8% of OM do, and points out that this is "a ratio of more than nine to one." This is a meaningless comparison, however--RM make up only 37% of his total population of millionaires, so his "more than nine to one" ratio is really nothing more than saying, of those millionaires who are religious, three-fourths hold religious practices which involve regular prayer (and 8% of those who do not consider themselves religious pray anyway). Since the OM population is much larger than the RM population, in absolute numbers that's not a nine-to-one ratio--his numbers show that about 28% of his total sample are RM who pray, while 5% of his total sample are OM who pray--closer to a six-to-one ratio.
But more importantly, the author glosses over the fact that not only are the majority of millionaires not religious, even a quarter of those who are don't engage in regular prayer! Given that the U.S. is one of the most religious countries in the world, the fact that such a low percentage of millionaires are religious is quite interesting and worthy of further exploration as to the cause, but for Stanley, religion and prayer are an important foundation of the "millionaire mind," and he completely misses the opportunity to find an explanation for why millionaires are so much less religious than the general population.
In a later table in the book on p. 366, he shows activities engaged in by a sample of 733 millionaires during the preceding 30 days. The table includes 52% attending religious services, 47% praying, 37% attending religious events, 22% Bible/devotional reading. These numbers don't quite match up with the RM/OM data from pp. 173-174, which seem to show even lower levels of religious activity, but these are still lower than they are for the nonmillionaire population--and weekly church attendance is notoriously over-reported in surveys. Work by Mark Chaves, C. Kirk Hardaway, and P.L. Marler in the 1990s found the actual percentage of attendance about half of what surveys show. This actually could mean that millionaires attend more often, if Stanley's survey results don't have similar over-reporting.
The author's religious bias further leads him to recommend to a student going through a divorce that she, despite not being a church attendee, search for a mate by joining a church group (p. 268) because she "believed in marriage and the traditional family concept." He writes that "I believe that one is likely to find better prospects in a church setting than in singles bars. Of course, there are no guarantees, but people with a religious orientation are more prone to respect the principles espoused in the Good Book." But why is he just guessing on this? Hasn't he asked his population of millionaires--the ones who are 63% non-religious--how they met their mates? He did this, very usefully, regarding how millionaires purchase their homes (pp. 315-326)--yet isn't picking a partner even more important?
This book has some interesting data, and is at its best when giving comparative results between populations (e.g., the house-purchasing characteristics of economically productive millionaires vs. non-economically productive millionaires in chapter 7). But it doesn't stand up well in comparison to The Millionaire Next Door, which is a much better book.