Do all social species really need brain to brain coupling for communication?

This is my essay on the question asked at the end of the first session:

First of all I read some text on the internet and found that there are some species that are not social in the coverage of social definition, like Snakes & Tortoise; this is what I didn't think so before.

Anyway, in my opinion it is not a necessity to assign brain to brain coupling mechanism for all of social species; they may have some physical limbs (e.g. like wireless radar senders and receivers) to generate some kinds of communicative signals or they may use some kinds of body gestures which are instinctively or genetically defined to have a special meaning for them and can help them communicate with each other. Assuming these, there is no certain need to consider learning nor developing mechanism for them.

But for humans I think the case is different, meaning that in human’s interactions, they pass a learning process to be able to make a brain to brain coupling although the process might be very fast, unintended and not easily detectable. One possible mechanism for this learning could be synchrony, why not?; meaning that in the examples we saw in the paper, the two brains start to reach to a common frequency and phase, these characteristics may be one of the people’s who is acting dominantly or something between theirs.

I don’t exactly know what null hypothesis we are rejecting when we subscribe to the brain-to-brain coupling hypothesis, but I think there are many intuitive evidence in higher order levels of coupling that lead us to believe such a thing in lower levels. For instance telepathy or dreaming some friend who you have not heard of her for long calling you and the next day you receive an email of her (which has happened many times for me)

If we understand the nature of these seemingly coupling mechanism we can account for some daily phenomena like first impression which is vastly discussed in social psychology. Also we can understand which couples or people can have a better performance in their acting so that we can have more successful small socials in life or work and so on.   

Session 1 | Brain-to-brain coupling: a mechanism for creating and sharing a social world

On our first session we discussed: Hasson, Uri, et al. "Brain-to-brain coupling: a mechanism for creating and sharing a social world." Trends in cognitive sciences 16.2 (2012).

Bahador presented the paper for us, we had several problems in understanding different parts like first paragraph second page, where they claim that : 

Brain-to-brain coupling is analogous to a wireless communication system in which two brains are coupled via the transmission of a physical signal (light,sound, pressure or chemical compound) through the shared physical environment.

The phrase "wireless communication" was ambiguous to us, does it mean that we should strictly use a wireless technology to create a brain-to-brain coupling?
As we were going through the paper, we reached to the question "are all species social?", do we really need a "brain-brain" communication to understand complex behaviors?