It sounds like they want a representative sample, which isn’t something I’d be confident in my ability to help them with directly, so I’d advise them to first scan for a person who’s very experienced in statistical sampling and to then work with that person to determine a strategy that will meet their goals.

If they weren’t on board with that plan, then I’d see if they were willing to share their target sample size. If I didn’t have an option for the count I would assume they would be contacting 1% of the population (80 million people). I’d also let them know that being representative and selecting for traits that will make encounters go smoothly are conflicting goals, so I’m prioritizing for representation and they can figure out the “please don’t pull a shotgun out, human!” trait on their own. Depending on all that, I’d recommend an approach that accounted for as much of the following as possible.

• gender (male, female, non-binary)
• race
• culture and sub-culture (so this would include everything from religion to music to hobbies)
• profession
• age, broken down into micro-generations
• mix of neurotypical and neurodivergent
• different varieties of neurodivergence
• range of intelligences

My immediate instinct is to lead them towards people like agorophobes or alien fetishists, because that would be funny. They should maybe have asked someone else.

A serious answer is that it probably matters more how they make contact than who they contact, if they want representative. People hide their true colours in big moments like that, so if they can make it less obvious they're aliens that's good.

Cool under pressure maybe? I expect a lot of people would freak out upon meeting an alien which is probably pretty inefficient. And smart is presumably a benefit. That's not really representative of most humans though lol

Nobody who is an aliens conspiracy person, they wouldn't be believed. Schizophrenia I think would let someone receive telepathy but again, unreliable.

If they can abduct me, and communicate with me, why do they want to communicate telepathically with the rest of humanity, why not contact using technology, our technology? If they were so very different there is no way they could communicate that idea to me clearly.

Run alien Run!

You can either get something that is representative, so the median, by choosing mid traits (mid spiritualistic, mid artistic, mid intro/extroverted, med IQ), or by choosing at random. Everything else would not be representative, and depending on your own traits, you would be biased - eg. non spiritualistic, non artistic, introverted, anxious, mid IQ, technology oriented, but also trans and depressed. Some of those I would obviously not see as an average trait, but being atheist and non-spiritualistic would definitely be on my list, despite not being the actual norm.