The report also found substantial improvement in investment decisions as people aged. Older investors were much less likely to trade too often, try to time the market or base investments on short-term considerations.

They were also more satisfied with their financial situation.

Barclays Wealth also found that women are better long-term investors than men, who tend to take more risks and are more likely to favor frequent trading and efforts to time the market.

"Women tend to have lower composure and a greater desire for financial self-control, which is associated with a desire to use self-control strategies," the report said.

"Women are also more likely to believe that these strategies are effective." As a consequence, women tended to trade less and earn higher returns over time.

Barclays Wealth sponsored surveys of more than 2,000 people from 20 countries who had at least $1.5 million in investment assets, including 200 with at least $15 million. These investors may not have known the details of their emotional flaws as documented by behavioral economists. But they were aware that they were prone to bad decisions and were open to getting help.

The report identified seven self-control strategies to help people counter their tendencies to make bad decisions. The use of these strategies was not limited to investments and often included other behaviors, such as big-ticket purchases or dieting and exercise.

Here are the seven strategies and their application to financial decisions:

1. Limit the options. Purchase illiquid investments to avoid the urge to sell investments when the market is falling.

2. Avoidance. Avoid information about how the market or portfolio is performing in order to stick to a long-term investment strategy.

3. Rules. Establish and use rules to help make better financial decisions, such as spend only out of income and never out of capital.

4. Deadlines. Set financial deadlines. For example, aim to save a certain amount of money by the end of the year.

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5. Cool off. Wait a few days after making a big financial decision before executing it.

6. Delegation. Delegate financial decisions to others, such as allowing an investment adviser to manage your portfolio.

7. Other people. Use other people to help reach financial goals. An example would be meeting with a financial adviser to make and execute a financial plan.

This article was reported by Philip Moeller for U.S. News & World Report.