I'm going to go out on a limb here and say that giving money to strangers in Paris might reflect on your cultural upbringing, and possibly personal issues. If it makes you feel better to do this, that's fine, but you should be aware of what really goes on. I volunteer with the food banks, soup kitchens and refugee relief efforts in Paris, so perhaps can explain things a little better.
Though there are some "independent contractors" who work alone and do live on the money people give them, most often the money that you give - to a homeless family, to an apparently physically or mentally handicapped person, to someone with an animal, to the "petition girls" or anyone selling souvenirs on the fly - is turned over at the end of the day to a "clan chief". There is always someone in the near vicinity watching them work - usually you wouldn't notice them, or would just take them for another beggar.
If the women, children and men do not bring in enough money to suit the chief, they are beaten or otherwise punished - a popular punishment is to force a woman to lie face down with an empty cup beside her on a heavily-trafficked sidewalk - or sold to another chief where she will be raped and likely end up pregnant. Children from other countries are often sold to a chief when their families can't pay their debt to him, and are smuggled to France. The term for this is "white slavery", no matter what the ethnic origin of the people involved, and it should not be supported.
Most of these "workers" are rounded up at the end of the day in vans, and driven to campsites in the Bois de Boulogne or in camps set up along abandoned railroad tracks. The clan chief is in charge of the care and feeding of his workers, and is responsible for sending money back to the "godfather" of all clans, who lives like a king, usually in Romania and Bulgaria. There was a recent undercover operation in Paris which exposed and convicted one of the major "godfathers", and the number of "petition girls", "gold ring scams", bottled water and souvenir sellers diminished for a few months. But another chief has taken control of things, so everyone is back at work.
If you have had personal experience with family members or friends who found themselves in difficult situations, that is quite another issue, and it is right and normal to do what you can to help them.
It should not be confused with the fact that the City of Paris makes nightly rounds - called "maraudes" - in all neighborhoods to check on people who are in need - volunteer doctors, nurses, and charity workers deliver free hot meals, water, blankets, medical care and psychological support. There are food banks and semi-annual food drives, to which most residents contribute. There is even an association which provides free pet food and veterinary care to the animals which are kept as companions by many homeless people. There are shelters, though many "street people" prefer to remain outdoors, for their own personal reasons. When the weather turns too hot or too cold, more shelter areas are commandeered so that people won't have to suffer outside.
It's not likely that you will see any of this in action, because the "maraudes" take place late in the evening and in the early morning. The shelters and food banks are located in unused office or school buildings, not in "tourist central".
But there is help available, and the people who need it know when and where to find it - for free.
