This BBC documentary reviews a number of methods for measuring love that have enjoyed some success. To summarize:

• Dr. Angela Rowe of the University of Bristol presents subjects with unfavourably distorted, unindistorted, and favourably distorted photographs of their love partners, and asks them to identify the undistorted one. Subjects in love tend to select photographs distorted in favour of their partner, while others select undistorted or unfavourably distorted photos.
• Bartels & Zeki (2000) identify differences in fMRI images of the brain while showing subjects in the early stages of their relationships photos of their love partners as compared to photos of controls. When viewing their love partners, areas of the brain associated with pleasure light up while areas associated with critical thinking are inhibited.
• Harker & Keltner (2001) claim they can predict romantic love and relationship success from college yearbook photos.

Here is another interesting one:

• Marazziti et al (1999) found that there are neurochemical markers (density of the platelet 5-HT transporter) for romantic love that are indistinguishable from severe OCD (they won an Ig Nobel prize for this).

This BBC documentary reviews a number of methods for measuring love that have enjoyed some success. To summarize:

• Dr. Angela Rowe of the University of Bristol presents subjects with unfavourably distorted, unindistorted, and favourably distorted photographs of their love partners, and asks them to identify the undistorted one. Subjects in love tend to select photographs distorted in favour of their partner, while others select undistorted or unfavourably distorted photos.
• Bartels & Zeki (2000) identify differences in fMRI images of the brain while showing subjects in the early stages of their relationships photos of their love partners as compared to photos of controls. When viewing their love partners, areas of the brain associated with pleasure light up while areas associated with critical thinking are inhibited.
• Harker & Keltner (2001) claim they can predict romantic love and relationship success from college yearbook photos.

Here are some others of interest:

• Marazziti et al (1999) found that there are neurochemical markers (density of the platelet 5-HT transporter) for romantic love that are indistinguishable from severe OCD (they won an Ig Nobel prize for this).
• Masuda (2003) does a meta-analysis of several love scales, from Zick Rubin's original Love Scale (1970), to the popular Passionate Love Scale (PLS) (1986), to John Alan Lee's Color Theory of love (1973).

This BBC documentary reviews a number of methods for measuring love that have enjoyed some success. To summarize:

• Dr. Angela Rowe of the University of Bristol presents subjects with unfavourably distorted, unindistorted, and favourably distorted photographs of their love partners, and asks them to identify the undistorted one. Subjects in love tend to select photographs distorted in favour of their partner, while others select undistorted or unfavourably distorted photos.
• Bartels & Zeki (2000) identify differences in fMRI images of the brain while showing subjects in the early stages of their relationships photos of their love partners as compared to photos of controls. When viewing their love partners, areas of the brain associated with pleasure light up while areas associated with critical thinking are inhibited.
• Harker & Keltner (2001) claim they can predict romantic love and relationship success from college yearbook photos.

This BBC documentary reviews a number of methods for measuring love that have enjoyed some success. To summarize:

• Dr. Angela Rowe of the University of Bristol presents subjects with unfavourably distorted, unindistorted, and favourably distorted photographs of their love partners, and asks them to identify the undistorted one. Subjects in love tend to select photographs distorted in favour of their partner, while others select undistorted or unfavourably distorted photos.
• Bartels & Zeki (2000) identify differences in fMRI images of the brain while showing subjects in the early stages of their relationships photos of their love partners as compared to photos of controls. When viewing their love partners, areas of the brain associated with pleasure light up while areas associated with critical thinking are inhibited.
• Harker & Keltner (2001) claim they can predict romantic love and relationship success from college yearbook photos.

Here is another interesting one:

• Marazziti et al (1999) found that there are neurochemical markers (density of the platelet 5-HT transporter) for romantic love that are indistinguishable from severe OCD (they won an Ig Nobel prize for this).