If you are hungry and thirsty at the same time, what would you do? Will you have food first or water?
Thirst is a “stronger” need than hunger. Likewise, if you are very very thirsty, but someone has put a choke hold on you and you can’t breath, which is more important? The need to breathe, of course.
This led Abraham Maslow to define a model that implies that while people aim to meet basic needs, they seek to meet successively higher needs in the form of a pyramid. This has come to be known as Maslow's hierarchy of needs. They are quoted and taught widely to students in Psychology.
In Maslow's pyramid, the lower the needs in the hierarchy, the more fundamental they are and the more a person will tend to abandon the higher needs in order to pay attention to sufficiently meeting the lower needs. For example, when we are ill, we care little for what others think about us: all we want is to get better.
The first four needs from the bottom of the pyramid are triggered when we have a deficit. Only self-actualization is a need that we seek for solely positive reasons. In practice, this hierarchy is only approximate and you do not have to have your physiologically needs fully satisfied before going on to seeking higher needs.
Physiological needs are to do with the maintenance of the human body. If we are unwell, then little else matters until we recover. As per Maslow, these are in fact individual needs, a lack of which, for example, Vitamin-C, will lead to a very specific hunger for things. Something that the body has got Vitamin-C from in the past - e.g. orange juice.
Safety needs are about putting a roof over our heads and keeping us from harm. If we are rich, strong and powerful, or have good friends, we can make ourselves feel safe. In an average adult, this set of needs manifest themselves in the form of urges to have a home in a safe neighbourhood, a little job security and a nest egg, a good retirement plan and a bit of insurance etc.
Love and Belonging needs introduce our tribal nature. When physiological needs and safety needs are, by and large, taken care of, a third layer starts to show up. You begin to feel the need for friends, a sweetheart, children, affectionate relationships in general, even a sense of community. In our day-to-day life, we exhibit these needs in our desires to marry, have a family, be a part of a community.
Esteem needs are for a higher position within a group. There're two versions of esteem needs, a lower one and a higher one. The lower one is the need for the respect of others, the need for status, fame, glory, recognition, attention, reputation, appreciation, dignity, even dominance. The higher form involves the need for self-respect, including such feelings as confidence, competence, achievement, mastery, independence, and freedom.
Self-actualization needs are to 'become what we are capable of becoming', which would our greatest achievement. They involve the continuous desire to fulfil potentials, to “be all that you can be.” They are a matter of becoming the most complete, the fullest, “you” -- hence the term, self-actualization.
Now, in keeping with this theory, if you want to be truly self-actualizing, you need to have your lower needs taken care of, at least to a considerable extent. For example, if you are hungry, you are scrambling to get food; If you are unsafe, you have to be continuously on guard; If you are isolated and unloved, you have to satisfy that need; If you have a low sense of self-esteem, you have to be defensive or compensate. When lower needs are unmet, you can’t fully devote yourself to fulfilling your potentials.
Do you think it is any surprise then, that only a small percentage of the world’s population is truly, predominantly, self-actualising?