If your machine meets the tech specs for PSE 11 then it should install. Per thew specs found at:
http://www.adobe.com/products/photoshop-elements/tech-specs.html
Mac OS
- Multicore Intel® processor
- Mac OS X v10.6 through v10.8
- 1GB of RAM (2GB for HD video functions)
- 4GB of available hard-disk space (additional free space required during installation)
- 1024x768 display resolution
- DVD-ROM drive
- QuickTime 7 software required for multimedia features
- Internet connection required for Internet-based services*
