When I consider the vastness of the Universe and some of the important discoveries that science has made thus far, I cannot help but conclude that a great variety of non-human races must live in the cosmos. To consider the negative or positive impact of those alien races that have been visiting for eons, I turn to Earth itself for answers.
Among Earth’s 6.3 billion people, there are 196 different countries, 9 major religions and 10 major languages. The result is a tremendous variety of philosophies and customs that can promote, in extreme cases, vastly different views and behavior. We all recognize how different the actions of extremist religionists can be when compared to more traditional religions. As for customs, if we compare a person raised in a sophisticated society to someone from New Guinea, for example, we also see radical differences in agendas and behavior. Yet, they are all members of the human race. With Earth as an example, it would seem logical that such differences would also exist among the many non-human races living throughout the cosmos, including those visiting Earth.
Whether the impact of open ET contact upon our planet would be positive or negative would depend upon a number of factors:
Which races are visiting the planet?
What is the stage of their physical and technological development?
What are their customs and agendas?
Additionally, considering human variables, whether the alien behavior would be seen as positive or negative also depends upon the cultural, religious and psychological development of the person perceiving the alien activity. For example, at first glance, some might see the presence of any alien race from a positive perspective as a spiritual opportunity, or from a negative view as a terribly evil presence. Others might investigate and consider the matter more fully (yet, inevitably filtered through their own conditioned perspective), and come to a mixed conclusion that the visitors’ intentions are to uplift humanity, exploit humanity or both.
Ultimately, I believe the effect upon humans and our planet by the alien presence is potentially both positive and negative, dependent upon which species is involved.