I have had interaction with Indians, sri lankans and bengalis in different countries.
Bengalis... Friendly, helpful, open up quickly to invitations, good sense of humour.....as colleagues :i found them dedicated and hard workers. Will help without being asked. Laid back but alert at work at same time.
Sri Lankans.....Can be reserved at times, good sense of humour though....as colleagues: they are ok, dont open quickly like Bengalis. will help when asked.
Indians....lots of varieties,as colleagues : very vocal in the workplace, helpful only if you ask them, soft spoken, sometimes timid (dont take pangas with anyone), i hardly saw any indian getting aggressive. laid back but not lazy.
Pakistanis......at workplace, very emotional and aggressive, extremely vocal, 24/7 Ready to take "panga" with HR and management, nakhray toba
Hyper active.
Lethal Combo : If there is a group of 3-5 Indians-pakistani friends at a workplace, they can take on the whole workplace on their own
There is no stopping to them
Gora afriki arbi chinese philipino ...har koi panah maangay ga
As neighbours and friends, all three nationalities (Bengalis/Sri Lankans/Indians) make very good friends visiting each other homes and families and kids mingling up and lots of laughter and humour. never had any issues.