Final answer:
The author assumes that fulfilling a range of physical, psychological, and social needs, including social interaction and securing possessions, is necessary for attaining happiness.
Step-by-step explanation:
One assumption the author makes about attaining happiness is that a person needs social interaction and the ability to secure goods they acquire to be happy. As humans, we have physical, psychological, and social needs that must be fulfilled to achieve happiness. Our needs extend beyond basic necessities like food, water, and shelter to include social networks and the security of our possessions. The complexity of these systems enhances our ability to access a variety of items that contribute to our happiness, but also increases the need to secure what we have acquired. In essence, happiness is tied to the satisfaction of a range of needs and desires, including those involving social interactions and material possessions.