As of right now, science acknowledges there are SIX densities of consciousness
First Density - The consciousness of life in its simplest expressions
Single celled organisms, bacteria, cells, and organ systems, are examples of first density consciousness. Life in first density is pre-programmed. Once alive, a cell doesn't have to be taught how to be a cell, it just knows what to do. Life at this level doesn't get choice, it simply is. First density systems respond with primordial reactions to circumstances. These reactions usually take the form of a chemical reaction which helps survival. This density is the building block of all other densities of consciousness.
Second Density - The consciousness that occurs with the emergence of instinct
It is the primary density of most animals. The first density systems of life create urges, like the desire to eat or reproduce, which the second density consciousness being can choose to act on or not. This choice is usually governed by survival. If a mouse sees a really tasty seed but retrieving it means he might get eaten, it will make a choice on how to proceed. Choices are basically two dimensional - act or not act. Fight or flight.
Third Density - The consciousness marked by the emergence of a personal will and self-awareness
It is the density of more evolved animals and is the starting density for humans. In second density, choice is a two dimensional line - life can move in one direction or the other. With third density, choice also enters this dimension. The sense of will allows life to move in whatever direction it wants. Life begins making decisions having to do more with pleasure and love. Consciousness in this density becomes playful, especially as children. Third density animals often live in groups and develop a social protocol for how to live together. In humans, we call it morality. Where a second density-being would run at the first sign of danger, a third density-being may put itself in harm's way to protect something it loved or if it thinks it is the 'right' thing to do.
Each higher density needs the foundation of the densities beneath it
For example:
First and second density consciousness exists within humans. The various systems of the body are first density. They simply run. We cannot choose how quickly our liver filters blood, it just does it. Emotions are also a first density experience. While we eventually gain the ability to choose how we react to emotions, emotions themselves just are. Just as we have a stomach, we have emotions. There is no choice in the matter. Second density in humans is the survival mind - the ego. The ego has the ability to react or not react. The ego thinks dualistically, aka two-dimensionally. When the ego is command, it reduces infinite options to two.
Fourth, fifth and sixth density appear to be unique to humans on Earth
Fourth Density - The consciousness where we see the emergence of a sense of will through time
An inner sense of importance and direction. In third density, a human has will, but does not have an innate sense of how to apply that will. As a result, a human in third density consciousness allows the world around him to define what is important and what he should pursue with his will. That is why third density consciousness is often referred to as 'victim consciousness' - because one is being defined by the world around them. A human child with a healthy family life will naturally move from third density to fourth density during puberty. In our world now, few of us get the pleasure of a healthy, loving, nurturing family. As a result, many humans remain in third density consciousness their entire lives.
Even if one was raised in a dysfunctional family, they can still enter fourth density consciousness. To achieve this density, one must have an inner sense of self-worth. In in healthy family, this would emerge naturally. If one comes from a dysfunctional family, it just takes a little more work. They have to learn to foster self-worth and heal the emotional trauma preventing them from feeling like they can have what they want.
Humans have an inner drive to create in the world and make decisions on how to spend this energy. This decision could be made consciously or unconsciously. Some decide to use this drive for the benefit of themselves. Let’s call that approach "Service to Self." Others decide to use this drive to help others, an approach we'll call "Service to Others".
STS - (Service to Self) 
They are focused on their own advancement and goals. Driven by their ambition, they want what they want and nothing is going to get in their way. They are willing to burn bridges, take advantage of others, and manipulate in order to achieve their goals of attaining position, wealth and power. People who are STS are more likely to rise to positions of power in business and politics. While they say they are working for the good of others, all you have to do is look at their actions to see they are not. This is easy to see with politicians. While they say they are working to help the people, in most cases, they prioritize their own advancement.
STO (Service to Others) 
They are focused on spending their energy to further an ideal. They want to see the world become a better place. Driven by compassion, they work tirelessly to help uplift those around them. It is common to find people who are Service to Others working in non-profits and other high-impact but low paying positions. To them, the work is more important than their own success. That isn't to say they don’t work in well paying positions - they absolutely can.
Both STS and STO are imbalanced and lead to a depletion of energy. Service to Self-er's constant need for more prevents them from achieving happiness. They are chasing prestige, wealth and power because they think that is how one achieves happiness. They get the big house, 3 cars, a powerful position, a trophy partner, and all the stuff they could ever hope for, but are still empty inside. Eventually, despair begins to take over which brings about a tenancy for self-sabotage. Everything begins to fall apart. Their relationships become toxic, they often burn through their wealth, and their attitude and actions lead to them losing their position of power. This is often exasperated by an increase of alcohol or drug use to numb the emotional pain. Their life energy becomes so depleted, they become more susceptible to disease and early death.
Service to Other-ers have the opposite problem. Because they love helping those who are struggling, they often choose emotionally needy, third density partners and friends who constantly crave their energy as well as do work which is emotionally draining. Constantly prioritizing the needs of others before their own leads them to feeling emotionally and physically drained. Eventually, they will experience "burnout" and will not be able to give anymore. Since their relationships are often with the emotionally needy, when an STO burns out, they cannot provide the emotional support they did before and their friends and/or partner tend to move on to find someone else they can find emotional security in. Completely drained, they too become more susceptible to illness and early death.
Any system where energy only flows in one direction will eventually deplete itself. This is true in nature and it is true with people. If it does not rain, eventually the river will dry up. If the moisture disappears from a region, it leads to drought. In our universe, energy must flow back and forth for something to be sustainable. When one realizes they have to give in order to receive and they must receive in order to give, they begin to enter the fifth density of consciousness.
Fifth Density - The consciousness about attaining balance and self-actualization.
When energy flows in only one direction, it becomes depleted. But in fifth density, energy flows in two directions and tempers the energy draining qualities of forth density consciousness. In STS, one experiences their drive as desire and greed. The greed and desire fade in fifth density and are replaced with receptiveness and openness for being rewarded for their service. In STO, one experiences their drive as a constant need to give to others with little regard for how that energy is returned. As a result, they get taken advantage of. In fifth density, one is still very loving but isn't afraid of drawing boundaries if someone in their life is draining their energy. They will not engage in one sided relationships.
In this density, one develops a stronger sense of Self (with a big S) with STS and STO, self-worth originates from external factors - from getting and doing. Egoic pride begins to fade as one realizes they are where they are because they are part of something bigger. This allows them to act and receive out of selflessness. They lose the need to prove anything to anyone. With nothing to prove, one no longer feels the need to exhaust their internal drive and energy by constantly doing and getting. One finds healthy ways to keep their energy in balance. Without the need to define them self from external forces, one becomes truly comfortable with who they are.
Professionally, someone in STS will do whatever they need to do to advance and are prone to creating enemies. One advances by lifting up others. People gravitate towards those in fifth density and recognize their leadership ability and they tend to naturally advance in organizations. Fourth density breeds 'bosses' but in fifth density, one is seen as a 'leader' for their ability to inspire and create an enjoyable work environment. Others often view those in the fifth density as 'wise,' which is why fifth density is referred to as 'the density of wisdom.'
As one progresses through fifth density, they develop an ever deeper sense of inner peace. Eventually, they begin to ask bigger questions about life and start to wonder what is beyond achieving. By this point, they have already realized a deep truth: what you do to others, you do to yourself as well. What you put out is what you get back. They begin to see the connection between all things. No longer do they see the concepts of 'self' and 'other' as totally separate and this opens them to begin experiencing the final density. One first begins to experience sixth density with their first 'heart opening.' This deep sense of connection and love changes the 'experiencer' and they begin to understand the unity of the universe.
The Sixth Density - Unity Consciousness
After that first heart opening, their world has been rocked. Reality is not what they thought it was up to that point. When the heart opening experience fades, they return to their 'primary residence' of consciousness with a new drive - to understand and access this deeper experience of reality.
Where before, one was focused on the outer world, in Unity Consciousness, one begins looking within for truth. When one first gets a taste of Unity Consciousness, there are usually still plenty of unresolved conflicts in the other densities of their being. One discovers the key to awakening this Unity Consciousness is letting go of the old beliefs and emotions in conflict with their Authentic Self and truth. As they surrender these attachments, they shift into deeper states of being. Worries about the past and future fade away and one begins to naturally live in the present. One can still set goals, but begins losing the need to worry about outcomes.
As one continues to surrender attachments to cultural ideals, their true calling and purpose becomes more clear, like a song in their soul. Expressing this 'Soul Song' brings about a deep sense of joy and one begins to realize, they are a creator. They are the universe experiencing and creating itself. It is an incredibly strange, beautiful and humbling realization.
Up to this point in human history, the vast majority of the human population has existed in the third and fourth densities of consciousness, where the ego is the main driver of consciousness. Few, if any, in a community would reach fifth density and when they did, were often seen as community leaders. Sixth density was extremely rare to find and when it did emerge, would often have major impacts on culture.
That is beginning to shift. There are more people in fifth and sixth density now than any time in human history. And it’s not just because there are more humans alive today than ever before. The percentage of people reaching these states is increasing. It is likely because people have more access to information which helps you achieve fifth and sixth density consciousness, but there are other theories as well. Hawkins Map of Consciousness and densities are just two of many different ways of wrapping one's mind around the various experiences of consciousness.
