This is more for general interest and curiosity as opposed to an attempt to prove anything serious. These aren't the be all and end all of correlations; they're basically showing what MB types each Enneagram type is most likely to be.
1w9 ESTJ, ISTJ
1w2 ENFJ, ISFJ
2w1 ESFJ, ENFJ
2w3 ESFJ, ENFJ
3w2 ESFJ, ESTJ
3w4 ENTJ, ENFJ
4w3 INFJ, INFP
4w5 INFP, INFJ
5w4 INFP, INTP
5w6 INTJ, INTP
6w5 INTJ, ENTJ, ISFJ, ISTJ
6w7 ISFJ, ESFP
7w6 ENTP, ESTP, ENFP
7w8 ESTP, ESFP, ISTP
8w7 ENTJ, ESTJ
8w9 INTJ
9w8 INFP, ISFP
9w1 INFJ, ISFJ