As leadership traits literature goes, Jaques and Cason add a unique perspective. It provides insight into a key leadership characteristic--time horizon--that is largely untouched in other literature. This leadership trait gives some insight into a possible explanation of the Peter Principle, that is being promoted to your level of incompetence.
Jaques identified the length (complex time span) of a task an individual can handle alone and the mental ability to handle levels of complexity as key leadership traits. For example, if you have a house with a 30 year mortgage, does that mean you have a 30 year complex time span? Unfortunately, no, as the engaged time span was only the length of time from deciding to buy a house to closing. The payments are not a complex task, just a monthly deduction from your account.
Using the same example, if you decided to build your own home (not contract it out) the time span would be several years from inception, through planning, materials acquisition, land, framing, and finishing. In other words, there would be mental and physical focus during the entire process.
Jaques further notes that in order for a leader to be a resource, the leader needs to have greater time span than the people led. Peering further down the road brings a look at resources, materials, planning and people who will be needed to complete the task.
Characteristics of time span:
Read Jaques, E. & Cason (1994) Human Capability. Falls Church, VA, Cason Hall. Jaques and Cason have developed statistically reliable tools to assess time span and ability to mentally manage complexity. These tools should be considered as ways to choose high potential leaders.