Negative reinforcement, such as using horrific images and painting a bleak picture of people in poor countries, can deter people from getting involved with charities. Positive reinforcement, where consistent feedback is given and the people who are benefited are visible, can make charitable giving an ongoing positive experience.
The speaker suggests that charities should publicly set a standard amount of donation for their cause, instead of constantly asking for less and less. Additionally, leveraging peer pressure may help increase positive impact while reducing the costs of soliciting donations.