Solo or group ideation?

Design is typically a collaborative activity, at least for major projects that involve many stakeholders. But what about the early stages of the design process, in the phase of generating ideas? Does ideating on one's own result in substantially different ideas compared with ideating in a group (typically five or more people), including so called "brainstorming"? Research suggests that in the workplace people become less productive in a team compared to working alone. This phenomenon has been labelled "social loafing" whereby people are said to be less likely to feel personally accountable for the outcome of a task when they are working in group. So would the concept of social loafing apply to ideation? In other words, is there a change in motivation among ideators when the ideation task is shared in group work? This, of course, would depend on the task at hand, or the composition or dynamics of the group. Moreover, working together can motivate people to perform well but it can also lead to a loss of motivation because the individual contribution is not as visible. As in "who came up with the idea first, and who can take credit for it?". So ideating in group may be a mixed blessing. A way out of this dilemma would be to start ideating alone followed by discussing individual outcomes with the group.