3D (three or third dimensional) Consciousness in used in describing the limited perception of the world as being only that which is perceived in the physical. A person who limits their perceptions to the basic 5 senses would be considered a 3D person. Such a person would not have had an awakening experience and therefore not have fully developed Higher Sensory Perception or an ability to sense energy fields and their quality.
A 3D person is usually much more developed mentally than emotionally, leading them to perceive everything through their intellect. This results in dismissing Higher Sensory Perception experiences in others as well as in themselves.
3D people tend to criticize awakened people mainly because of lack of understanding or lack of personal experience. Lack of understanding many times results in fearful reactions leading to ridicule and aggressive attacks. However, in most cases this is due to NAA manipulation, gaslighting and/or Mind Control.
3D Reality of Fear
Invoke Fear: The purpose of the Manipulator or Controller is to manufacture as much fear as possible to create dread and terror in the minds of the people, so that they will avoid rising in groups and instead become weaker and disabled. To maintain this continual state of fear buried in life’s many stressors, as well as perceived threats to survival, means activating the fight or flight reaction in the human nervous system and Brain. Eventually this takes a serious toll on the overall health of the body and sanity of the mind, as it rapidly breaks down immunity, increases disease states and drives painful mental imbalances.
Starseed Role in 3D
So as Starseeds and as awakening people, one of our first and primary objectives, is to determine our mission and lessons for entering the 3D Consciousness realm, and that we undergo the self inquiry process about remembering who we really are, in terms of our Soul, spirit incarnation and our purpose. As we study the 3D system, we begin to understand that we have come to this earth to become Masters of comprehending complex levels of manipulation, deception, and illusion, as well as consciousness suppression because that is what the third dimensional system on earth actually is.
And in understanding that 3D Consciousness is completely based on manipulating many levels of deceptions and illusions for the benefit of the Controllers, who take advantage of their position to mind control others into submission to their agendas, this comprehension really assists us to employ more skill with Neutral Association when observing the extreme levels of Emotional Manipulation, Addiction and instinctual Pain Body manipulation that goes on in the third dimensional system. We notice that the majority of the human race is pretty much controlled by its lower instinctual Pain Body and/or addictive bodies. So fear, pain, pleasure, money, sex and power run this place. These are all vibrational qualities that are deeply instinctual and buried within the subconscious mind, and the lower emotional body of a human being that has not developed its higher spiritual bodies through Awakening, thus keeping them running in circles on the 3D treadmill. 
Three Layers of Ego
In order to understand the Internal Structures of Ego which we also refer to as Houses of Ego, it requires the awareness that there are three main layers the 1st Chakra of the Unconscious Mind, the 2nd Chakra of the Instinctual Mind and the 3rd Chakra of the Conscious Mind.
The three layers of mind work together to serve the functions of the ego in all human beings. Each energetic layer has separate functions yet all three layers are interconnected and directly impact each other. As we learn about the layers in the internal structure of the ego, this clarifies the purpose of identifying what the ego is and how it operates within us. When we understand how Ego Filters operates inside our mind we are better equipped to heal the energetic imbalances stemming from the Negative Ego or Predator Mind. 
3D Personality Matrix
- Separation of Worlds
- Fearing Spiritual Knowledge
- [Transcript-PSD #7 Starseeds]
- Internal Structures of Ego, August 2013 Newsletter