Why do shirren get a penalty to Cha?

[Yqatuba]

It says they work well together and are really interested in other cultures (giving them a bonus to culture and diplomacy). If anything, I would think a BONUS to Cha would make more sense.

[Garretmander]

Because they're really awkward about the whole thing.

But really, probably some game balance thing where they may have swapped roles a few times here and there.

[BigNorseWolf]

Imagine "The Fly" HeeeEEelllLLLLLPppPP MeeEeeEEEEE" voice in your head for 8 hours.

[Kishmo]

(I assume this wasn't missed, but just in case: for fancy talky bug peoples, as of COM there is a Shirren species stat array that gives +2 Cha +2 Int and −2 Str rather than the usual +2 Con, +2 Wis, and -2 Cha)

[Wesrolter]

Racial issues, they were former swarm and people could still be uncomfortable about it? As Kishmo has mentioned, there are alternate stats for them if you have a REALLY friendly bug

[John Mangrum]

If pressed I would play it that they're so accustomed to working well together by their communal nature that they aren't accustomed to having to really sell their ideas.

[Xenocrat]

The famously charismatic Germans and Japanese.

The famously working well together Italians.

[Claxon]

Honestly, it's best not to question why certain races get certain bonuses and penalties. It just is.

But also, as noted there is an alternate sub species option which does give a bonus to Cha.

Lastly, if it really bothers you, you could petition your GM to get rid of the normal racial bonuses and replace it with everyone getting a floating +2 to any stat they wish.