The key issue is how to achieve it? The Situational Leadership model is a good guide for developing individuals. However the key element in achieving personal ownership and initiative in a team is the words and actions that come from the Leader.
Consider each person's behaviours on a scale between Disenfranchised and Anarchy.
Team members who are disenfranchised, and don't do more than the minimum required, do not show ownership and initiative. Equally, we do not want team members who are into anarchy - these are the ones that don't keep to the rules that good governance requires.
What good ownership and initiative is having team members as close to the line of Anarchy, without crossing over. These are the team members who do more, take on more, achieve more, challenge more and are great employees.
Great leaders know that you can't say to someone "show more initiative" and expect them to show it. Helping someone to develop initiative is about providing them with a safe environment in which their confidence can grow to their maximum capability.
What managers and leaders can do is influence the level of ownership and initiative that their teams demonstrate by their actions and the words that come out of their mouths. Some words move an individuals behaviours to the left [towards disenfranchised] and some words move an individuals behaviours to the right.
Examples of words that move someone's behaviours to the left:
Examples of words that move someone's behaviours to the right: