Cofounder of CoveyLink and the FranklinCovey Global Speed of Trust Practice, Stephen M.R. Covey has established in his book The Speed of Trust a simple and meaningful formula that demonstrates the importance of trust in business and in our personal life as well. "Trust always affects two outcomes: speed and cost. When trust goes down, speed will also go down and costs will go up. When trust goes up, speed will also go up and costs will go down." Another simple formula can rely the level of maturity to trust: when people interact together, the more they are mature, the faster trust is established and the higher is the level of trust. In this case, maturity relies on each form of intelligence (SQ, EQ, IQ, PQ).