Personal and Interpersonal skills
One of the great errors of thinking in many modern businesses is the belief that job-specific technical skill is the key component required to achieve business outcomes.
Plenty of empirical and anecdotal evidence goes to show the contrary: a person's ability to manage themselves - their mind, their emotions, their stress levels - and their skill in interacting with others all play a crucial part in how effectively they contribute to any team.
A lack of skills in these areas can prove costly not just for the individual but the team and organisation they are part of. Look here for ways to invest in universal skills that really effect the bottom line.