What is Collective Intelligence?
Collective intelligence is the wisdom of crowds, or the intelligence of groups, the intelligence that arises from cooperation, competition, and other group dynamics. Interestingly, there are attributes of a group that can’t be found with individual members of a group, attributes include important behavioral phenomena related group decision making. This is sort of like how looking at a single cell in our body only paints part of the picture of how our body works. To understand what is happening fully, we have to look at the complex systems those cells form.
Why is Collective Intelligence Important?
Collective intelligence is important because we can use it to understand, affect, model, and organize small groups like teams, large groups like cultures, individuals, interpersonal relationships, technology, and communication tools better. The two of the main technologies humans use to expand our impact on the world around us are the physical tools we build and the communication tools we use to relate to each other. Both of these directly relate to the study of collective intelligence. 
With the above said, I suggest watching the videos on this page for a better understanding of how different people view the concept of collective intelligence.
Collective Intelligence, a basic overview of the concept.
TIP: Cognitive AI like IBM’s Watson or Google’s DeepMind are cognitive computers that use machine learning to “think like humans” by mimicking some aspects of human cognition. The technology is still new, but advances in computing can allow us to see levels of information that we have never seen before (like the unstructured data of the Internet of Things – IOT). The technology behind cognitive computing, Google search, big data, and more relies on advances in the study of collective intelligence, not in regards to physical groups of humans, but of the conceptual and mechanical systems we build.
Analysis Versus Synthesis Thinking and Collective Intelligence
Typical analytical western thinking (analysis) breaks down the elements of a system trying to understand the system through its individual parts. Synthesis looks at the relationships between parts and the functions of the system as a whole. If we combine analysis with synthesis, we can get a better idea of how the system works and can thus apply more efficient strategies to the system.
Systems Theory: 1 Analysis and Synthesis, a basic overview on systems thinking, the collective is a complex system.
Collective Intelligence as a Tool and Technology
As humans we build tools to do that which we couldn’t do otherwise, we build fire to keep warm and cook food, we build rulers and calculators to help us create straight lines for bridges, we build computers to help us perform calculations and share information, we build search engines to organize that information.
As humans we also utilize groups to do that which we couldn’t do alone, a team gathers resources to cook on with fire; a team builds a bridge that allows others to bypass natural obstacles; a society connects on Facebook to share ideas; a team connects at Google to improve search.
In regards to our utilization of groups and technology, collective intelligence is arguably one of the most central concept in the social sciences, economics, marketing, applied technological sciences, political sciences, world affairs, and our evolution and ability to survive as humans.
Social Cognition and Collective Intelligence. A lecture from MITSloan, more collective intelligence from MIT here.
Science Of Persuasion. You can analyze the IOT, or you can influence it. It used to be you needed money and power to influence society, now you just need a keyboard. The implications of this are vast.
TIP: See why NASA thinks collective intelligence is important in this article from 2004.
Advancing Collective Technology
The next step is for us to advance collective intelligence technologies, such as cognitive AI, to extend our toolset so we can compensate for our weaknesses better and expand on our strength.
With this above introduction to what is collective intelligence and why is it important, I invite you to watch this informative video. It provides an overview of the sociological science behind collective intelligence. There is also a video with Neil deGrasse Tyson, which explains the importance of social networks as a tool for interacting with the collective.
Nicholas Christakis: The Sociological Science Behind Social Networks and Social Influence.
Neil deGrasse Tyson vs. Ray Kurzweil On The Singularity. Ray Kurzweil explains how collective intelligence is the next step in evolution. Tyson rolls his eyes a bit, but it is absorbing and pertains directly to this topic.