Insight from the field of psychology can help trial lawyers win in the courtroom. Here's how.

1. How can I persuade clients and jurors? According to 40-plus studies involving 20,000 participants, the answer is simple. Use the words "but you are free to. . . ." These studies show that this technique doubles the likelihood of the person saying yes to the request.

Why is this? Humans innately want empowerment, free will and control. The right to say "no" is a practical, powerful and persuasive tool. This phrase conveys respect and affirms the other person's authority to choose whether to grant the request.

Using these exact five words is not critical. What matters is the allusion to an individual's free will and the implication that the recipient is in control.

2. How can I improve my trial skills? Visualization — mentally rehearsing the performance of a task — promotes learning. It doesn't replace physical practice, but it's an important addition.

Surgeons can walk through the physical movements required for an upcoming operation. One study, "Learning Basic Surgical Skills with Mental Imagery: Using the Simulation Center in the Mind," which was reported in the June 2008 issue of Medical Education, found that medical students trained in mental imagery performed better in live surgeries than those who only studied textbooks.

Litigators can use mental practice for critical aspects of trial, such as imagining responses to juror questions in voir dire, rehearsing opening statements and closing arguments, and seeing the chess game of expert-witness cross-examination. Incorporating mental practice can help trial lawyers feel better prepared, more relaxed and more confident.

3. How can I break bad habits? Psychologists use the term "context-dependent repetition" to refer to the process of developing habits. Drinking a beer every day after work is an example of context-dependent repetition. Each instance of cracking open an icy brew upon walking in the door from work reinforces the mental link between the context and the response to that context.

The most recent study in the area of habit formation looked at behaviors such as wanting to eat a piece of fruit or go for a run every day. Researchers discovered a curved relationship between practice and automaticity. On average, subjects in the study reached a plateau in automaticity after 66 days: After an individual practices a behavior for 66 consecutive days, she likely has formed a habit. However, the study revealed that the complexity of the behavior making up the habit caused large variances in these numbers, anywhere from 18 to 254 days.

Lawyers may want to list their constructive habits (being on time, being prepared, being considerate of others) and destructive habits (being late, being unprepared, being disrespectful to others), then ask trusted co-workers for feedback, both positive and negative. Then it's time to prioritize the list and start with the bad habit that will be relatively easy to stop. Once you have conquered that habit, move on to another one. After all, breaking bad habits is a good habit.

4. How much evidence can the jury handle? "Short-term memory" refers to information the brain currently is using that hasn't yet been stored in long-term memory. While there is some dispute, the consensus among experts is that the number of items people can hold in short-term memory is seven, plus or minus two.

However, a number of recent studies have focused on the idea of "chunking," mentally reorganizing material into shorter, more meaningful groups. A chunk typically is made up of three of four items, grouped together based on some common characteristic.

Inundating the jury can result in jurors only remembering a handful of facts. Litigators should pinpoint their most important pieces of evidence and present them in a manner that is both easily digestible and memorable. We recommend focusing on a few pieces of evidence each day, and grouping all of the evidence into a few broad categories (or chunks) so it is easier for the jurors to recall. The key points should be placed on a PowerPoint slide or a flip chart to help jurors stay focused on them.

5. Can I change my personality traits? Research over the last 15 years indicates that it's possible to change personality traits. Generally speaking, three aspects of personality are likely to change with aging: anxiety levels, friendliness and eagerness for novel experiences.

A study published in March in Social Indicators Research looked at the following traits: extroversion, agreeableness, openness to experience, conscientiousness and neuroticism. At different times throughout their lives, research participants answered numerous questions regarding their personality, their life experiences and their overall level of satisfaction with their life.

The researchers found that personality can change over time and these changes most often correlate with shifts in demographic variables, such as marital status, employment and income.

The researchers wanted to know what effect, if any, a personality change would have on life satisfaction. Would those who initially rated high in neurosis but who became less neurotic over time also become more satisfied with life?

Efforts to answer this question resulted in the most surprising result of the study: the existence of a very high correlation between changes in personality and changes in overall satisfaction with life. The researchers found that a shift in a personality trait has a greater effect on satisfaction with life than changes in one's life circumstances, such as economic status or marital status, as noted in their article, "Is Personality Fixed? Personality Changes as Much as 'Variable' Economic Factors and More Strongly Predicts Changes in Life Satisfaction."

With all the stress, anxiety and frustration that accompanies the practice of law, we believe lawyers should seek out things that will bring them happiness, fulfillment and purpose.

How to Pare Down a Case for the Jury

1. Be mindful that the jury can only retain a limited amount of information.

2. Limit critical information to three to five points per day.

3. Point out to jurors how what is happening in the trial relates to the critical information.

4. Make the critical information easy to understand and remember; and

5. Prominently display the critical information so that jurors are constantly reminded of its importance.