Post History

Something like this query should work for you:

```
MATCH (a:Person)-[:IS_SON]->()-[:WAS_BORN]->(b:Country)
WITH a, count(DISTINCT b) AS birthplaces
WHERE birthplaces = 1
RETURN a
```

Note that this query would return people who have parents with unknown birthplaces, since those paths won't be included in the `MATCH` clause. If you have that case in your database and want to exclude it, then I think you lose a little elegance:

```
MATCH (a:Person)-[:IS_SON]->(p:Person)
OPTIONAL MATCH (p)-[:WAS_BORN]->(b:Country)
WITH a, count(p) AS parents, count(b) AS birthplaces, count(DISTINCT b) as distinct_birthplaces
WHERE parents = birthplaces AND distinct_birthplaces = 1
RETURN a
```