My own personal growth has certainly been fueled at times by the insights that personality assessments and profiles have provided. But equally I've had and seen experiences with them that range from frustrating to demotivating and even damaging.
The paradox is that we're attracted to the simplification of the categories, and yet few of us fit exactly or neatly in any of those categories. The risk is that we engage with someone based on a category stereotype that we have only a cursory knowledge of, or that simply doesn't apply to the person or in that situation.
So is there a right time to use them?
For an individual
On an individual basis, for self-reflection and self-assessment, any time could be beneficial, especially if the experience is guided by someone with expertise in the assessment or tool. They can be useful foundations for individual coaching, and a coach can help steer the individual through any confusion, surprises or triggers in the profile. Building self-awareness should be a lifelong endeavor, and many of the different profiles and assessments can be complementary to each other, can affirm aspects from previous profiles, or can offer interesting contradictions that may build a more nuanced understanding of self.
If you take an online individual assessment without the benefit of a coach then I suggest viewing your results through the following filters:
What do I immediately agree with?
Would others who know me agree with this?
What doesn't sound like me so much / doesn't really resonate?
What do I disagree with?
This immediately gives you agency over the profile - it's not telling you who you are, it's just helping you reflect on or uncover what you already know, and allows you to position the results as just an input for your self-awareness. What you reject or question from a profile may be just as instructive as what you agree with, in terms of your continued self-discovery.
For a team
For teams, it's a little different. I've seen and experienced profiles used in the early stages of team formation as a sort of get-to-know-each-other activity, and there are risks with this. Have you ever had the experience where someone gives you a "heads-up" on someone you're going to be working with (whether good or bad), but your experience of actually working with that person is quite different than the expectation that was built from that information? Did it take some time and effort to undo your initial assumptions? Do you even wish you'd started to build a relationship from a blank slate, without that prior opinion?
The labels that these profiles provide can be similarly misleading, and can be detrimental if they form the basis of our first impressions of someone. Our social desire for belonging means that we often lean towards those who share our profile, but this works against what many of these instruments and tools aim to assert (when delivered professionally) - that a combination of styles, preferences and profiles is beneficial within the context of a team or organization.
My recommendation for new teams is to begin getting to know each other through activities that encourage sharing stories, values, passions and interests -- the sorts of things that are our natural go-tos when we want to learn about each other. As relationships begin to build, including through the work, it may then be appropriate to introduce profiles as an additional layer, rather than a foundational one.
Another time where it's not appropriate to use profiles within a team is to resolve dysfunction or tension. When viewed through a negative lens, profiles simply become reasons why someone is hard to work with, why they don't understand or why we're destined never to get along.
On the positive side, one of the best realizations that can come from sharing team profiles is where solid and productive relationships have already been built, and individuals realize they grew despite different or "opposite" profiles. In other words, this can underscore the power of diversity, of being complementary. It can motivate team members to further collaborate across differences.
If you do take a team through a profiles discovery and sharing exercise, I suggest positioning and exploring in the following order:
Which profile tool or assessment is best?
My experience with over a dozen profile tools is that while they each have their merits, individual or team situations may dictate which one may be more beneficial. That said, many of them overlap significantly and a skilled facilitator can adapt the tool to fit the needs of the audience. If you're interested in exploring an option for your team, send an enquiry here.