Table 1.

Comparison of the distribution of linguistic complexity (LC) values in real vs. randomly generated palindromes.

Length(X), Length(Y)	Average LC of the real set	Average LC of the random set	Level of significance in Mann-Whitney test
3,0	0.769	0.841	*
3,1	0.805	0.869	**
3,2	0.867	0.893	*
4,0	0.761	0.869	**
4,1	0.831	0.886	**
4,2	0.889	0.903	**
4,3	0.897	0.913	**
5,0	0.628	0.888	**
5,1	0.687	0.899	**
5,2	0.866	0.911	*
5,3	0.828	0.918	**
5,4	0.929	0.928	NS

For a definition of X and Y in a palindrome please see Methods. NS: non-significant difference; *: significant at the level of 0.05; **: significant at the level of 0.01.