Some similarities have been found in the glyphs between Rongorongo and Indus writing. As well, the direction of writing (boustrophedon) might be the same/similar to Indus. In addition to the correlation of glyphs found by de Hevesy that I've seen so far, I wonder if there might be other correlations in glyphs - (upright) fish, fish with wings/arms, bearer, the epicene plural glyph, etc.
Asked by Elango Cheran
There is no historical connection, only imaginary.
I am not sure. Many of the signs that are common seem to be generic strokes and I am not convinced they are greatly similar. Also, causality of how the script reached there is also a big question. One needs to set up standards of comparison using parameters such as the statistical distribution of number of strokes per sign, stylistic similarity etc. and then compare it with environment and likely similarity of words etc. But this has not been done by us for want of time. The problem can be reasonably defined.
Based on the discrepancy in the time period of existence of these two scripts and the vast distance between their places of occurrences the connection seems highly unlikely. However, further research can shed more light on this.
Above: Easter Island Rapa Nui Rongorongo Mama Script 2 Sided Wooden Tablet. Image courtesy of J.S. Tribal.