The rate of development

The rate of in individual’s Lectical growth (growth in complexity level) is affected by a wide range of factors. Twin studies suggest that about 50% of the variance in growth trajectories is likely to be predicted by genetic factors. The remaining variation is explained by environmental factors, including the environment in the womb, the home environment, parenting quality, educational quality & fit, economic status, diet, personal learning habits, and aspects of personality.

Each Lectical Level takes longer to traverse than the previous level. This is because development through each successive level involves constructing increasingly elaborated and abstract knowledge networks. Don’t be fooled by the slow growth, though. A little growth can have an important impact on outcomes. For example, small advances in level 11 can make a big difference in an individual’s capacity to work effectively with complexity and change — at home and in the workplace.

The graph above shows examples of possible learning trajectories. Note that the highest age shown on this graphs is 60. This does not mean that individuals cannot develop after the age of 60.

The yellow circle in each graph represents a Lectical Score and the confidence interval around that score. That’s the range in which the “true score” would most likely fall. When interpreting any test score, you should keep the confidence interval in mind.

Within individuals, growth is not tidy

When we measure the development of individuals over short time spans, it does not look smooth. The kind of pattern shown in the following graph is more common.

People don’t grow at the same rate in every knowledge area

An individual’s rate of growth depends on the level of their immersion in particular knowledge areas. A physicist may be on one trajectory when it comes to physics and quite a different trajectory when it comes to interpersonal understanding.

Additional factors that affect the rate of development

• Practice effect: In late adolescence and adulthood, individuals often demonstrate an apparent spurt of growth between their first and second assessments. One possible contributing factor is the practice effect. Many people have never taken an assessment that requires in-depth explanations of their thinking. They may do better on their second test time than on their first, because they’ve learned to explain their answers more fully, not necessarily because they have grown.
• Tacit knowledge: Another possible reason for an apparent growth spurt between test times 1 and 2, can be attributed to tacit knowledge. Some people may have a great deal of practical knowledge or skill, but because their jobs don’t require them to explain their thinking on a regular basis, most of this knowledge is “tacit”—meaning that it is largely unconscious. Following their first assessment, if these individuals engage in the right kind of learning experience, they can make a great deal of their tacit knowledge more explicit, resulting in an apparent growth spurt.
• Historical developmental trajectory. As time passes, a person whose history places her on a particular curve is less and less likely to jump to a higher curve.
• Learning in the moment. Individuals who VCoL continuously as a habit of mind grow better and faster than those who do not.
• Participation in formal learning opportunities that are rich in VCoLs. Educational programs that foster robust learning with VCoL-rich activities help people learn faster and better.